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  <h1>Source code for django.utils.timezone</h1><div class="highlight"><pre>
<span class="sd">&quot;&quot;&quot;</span>
<span class="sd">Timezone-related classes and functions.</span>

<span class="sd">This module uses pytz when it&#39;s available and fallbacks when it isn&#39;t.</span>
<span class="sd">&quot;&quot;&quot;</span>

<span class="kn">from</span> <span class="nn">datetime</span> <span class="kn">import</span> <span class="n">datetime</span><span class="p">,</span> <span class="n">timedelta</span><span class="p">,</span> <span class="n">tzinfo</span>
<span class="kn">from</span> <span class="nn">threading</span> <span class="kn">import</span> <span class="n">local</span>
<span class="kn">import</span> <span class="nn">sys</span>
<span class="kn">import</span> <span class="nn">time</span> <span class="kn">as</span> <span class="nn">_time</span>

<span class="k">try</span><span class="p">:</span>
    <span class="kn">import</span> <span class="nn">pytz</span>
<span class="k">except</span> <span class="ne">ImportError</span><span class="p">:</span>
    <span class="n">pytz</span> <span class="o">=</span> <span class="bp">None</span>

<span class="kn">from</span> <span class="nn">django.conf</span> <span class="kn">import</span> <span class="n">settings</span>
<span class="kn">from</span> <span class="nn">django.utils</span> <span class="kn">import</span> <span class="n">six</span>

<span class="n">__all__</span> <span class="o">=</span> <span class="p">[</span>
    <span class="s">&#39;utc&#39;</span><span class="p">,</span>
    <span class="s">&#39;get_default_timezone&#39;</span><span class="p">,</span> <span class="s">&#39;get_default_timezone_name&#39;</span><span class="p">,</span>
    <span class="s">&#39;get_current_timezone&#39;</span><span class="p">,</span> <span class="s">&#39;get_current_timezone_name&#39;</span><span class="p">,</span>
    <span class="s">&#39;activate&#39;</span><span class="p">,</span> <span class="s">&#39;deactivate&#39;</span><span class="p">,</span> <span class="s">&#39;override&#39;</span><span class="p">,</span>
    <span class="s">&#39;localtime&#39;</span><span class="p">,</span> <span class="s">&#39;now&#39;</span><span class="p">,</span>
    <span class="s">&#39;is_aware&#39;</span><span class="p">,</span> <span class="s">&#39;is_naive&#39;</span><span class="p">,</span> <span class="s">&#39;make_aware&#39;</span><span class="p">,</span> <span class="s">&#39;make_naive&#39;</span><span class="p">,</span>
<span class="p">]</span>


<span class="c"># UTC and local time zones</span>

<span class="n">ZERO</span> <span class="o">=</span> <span class="n">timedelta</span><span class="p">(</span><span class="mi">0</span><span class="p">)</span>

<span class="k">class</span> <span class="nc">UTC</span><span class="p">(</span><span class="n">tzinfo</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    UTC implementation taken from Python&#39;s docs.</span>

<span class="sd">    Used only when pytz isn&#39;t available.</span>
<span class="sd">    &quot;&quot;&quot;</span>

    <span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">return</span> <span class="s">&quot;&lt;UTC&gt;&quot;</span>

    <span class="k">def</span> <span class="nf">utcoffset</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="k">return</span> <span class="n">ZERO</span>

    <span class="k">def</span> <span class="nf">tzname</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="k">return</span> <span class="s">&quot;UTC&quot;</span>

    <span class="k">def</span> <span class="nf">dst</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="k">return</span> <span class="n">ZERO</span>

<span class="k">class</span> <span class="nc">ReferenceLocalTimezone</span><span class="p">(</span><span class="n">tzinfo</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Local time implementation taken from Python&#39;s docs.</span>

<span class="sd">    Used only when pytz isn&#39;t available, and most likely inaccurate. If you&#39;re</span>
<span class="sd">    having trouble with this class, don&#39;t waste your time, just install pytz.</span>

<span class="sd">    Kept identical to the reference version. Subclasses contain improvements.</span>
<span class="sd">    &quot;&quot;&quot;</span>

    <span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="c"># This code is moved in __init__ to execute it as late as possible</span>
        <span class="c"># See get_default_timezone().</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">STDOFFSET</span> <span class="o">=</span> <span class="n">timedelta</span><span class="p">(</span><span class="n">seconds</span><span class="o">=-</span><span class="n">_time</span><span class="o">.</span><span class="n">timezone</span><span class="p">)</span>
        <span class="k">if</span> <span class="n">_time</span><span class="o">.</span><span class="n">daylight</span><span class="p">:</span>
            <span class="bp">self</span><span class="o">.</span><span class="n">DSTOFFSET</span> <span class="o">=</span> <span class="n">timedelta</span><span class="p">(</span><span class="n">seconds</span><span class="o">=-</span><span class="n">_time</span><span class="o">.</span><span class="n">altzone</span><span class="p">)</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="bp">self</span><span class="o">.</span><span class="n">DSTOFFSET</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">STDOFFSET</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">DSTDIFF</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">DSTOFFSET</span> <span class="o">-</span> <span class="bp">self</span><span class="o">.</span><span class="n">STDOFFSET</span>
        <span class="n">tzinfo</span><span class="o">.</span><span class="n">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">)</span>

    <span class="k">def</span> <span class="nf">__repr__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">return</span> <span class="s">&quot;&lt;LocalTimezone&gt;&quot;</span>

    <span class="k">def</span> <span class="nf">utcoffset</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_isdst</span><span class="p">(</span><span class="n">dt</span><span class="p">):</span>
            <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">DSTOFFSET</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">STDOFFSET</span>

    <span class="k">def</span> <span class="nf">dst</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">_isdst</span><span class="p">(</span><span class="n">dt</span><span class="p">):</span>
            <span class="k">return</span> <span class="bp">self</span><span class="o">.</span><span class="n">DSTDIFF</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="k">return</span> <span class="n">ZERO</span>

    <span class="k">def</span> <span class="nf">tzname</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="n">is_dst</span> <span class="o">=</span> <span class="bp">False</span> <span class="k">if</span> <span class="n">dt</span> <span class="ow">is</span> <span class="bp">None</span> <span class="k">else</span> <span class="bp">self</span><span class="o">.</span><span class="n">_isdst</span><span class="p">(</span><span class="n">dt</span><span class="p">)</span>
        <span class="k">return</span> <span class="n">_time</span><span class="o">.</span><span class="n">tzname</span><span class="p">[</span><span class="n">is_dst</span><span class="p">]</span>

    <span class="k">def</span> <span class="nf">_isdst</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="n">tt</span> <span class="o">=</span> <span class="p">(</span><span class="n">dt</span><span class="o">.</span><span class="n">year</span><span class="p">,</span> <span class="n">dt</span><span class="o">.</span><span class="n">month</span><span class="p">,</span> <span class="n">dt</span><span class="o">.</span><span class="n">day</span><span class="p">,</span>
              <span class="n">dt</span><span class="o">.</span><span class="n">hour</span><span class="p">,</span> <span class="n">dt</span><span class="o">.</span><span class="n">minute</span><span class="p">,</span> <span class="n">dt</span><span class="o">.</span><span class="n">second</span><span class="p">,</span>
              <span class="n">dt</span><span class="o">.</span><span class="n">weekday</span><span class="p">(),</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">0</span><span class="p">)</span>
        <span class="n">stamp</span> <span class="o">=</span> <span class="n">_time</span><span class="o">.</span><span class="n">mktime</span><span class="p">(</span><span class="n">tt</span><span class="p">)</span>
        <span class="n">tt</span> <span class="o">=</span> <span class="n">_time</span><span class="o">.</span><span class="n">localtime</span><span class="p">(</span><span class="n">stamp</span><span class="p">)</span>
        <span class="k">return</span> <span class="n">tt</span><span class="o">.</span><span class="n">tm_isdst</span> <span class="o">&gt;</span> <span class="mi">0</span>

<span class="k">class</span> <span class="nc">LocalTimezone</span><span class="p">(</span><span class="n">ReferenceLocalTimezone</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Slightly improved local time implementation focusing on correctness.</span>

<span class="sd">    It still crashes on dates before 1970 or after 2038, but at least the</span>
<span class="sd">    error message is helpful.</span>
<span class="sd">    &quot;&quot;&quot;</span>

    <span class="k">def</span> <span class="nf">_isdst</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">dt</span><span class="p">):</span>
        <span class="k">try</span><span class="p">:</span>
            <span class="k">return</span> <span class="nb">super</span><span class="p">(</span><span class="n">LocalTimezone</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">_isdst</span><span class="p">(</span><span class="n">dt</span><span class="p">)</span>
        <span class="k">except</span> <span class="p">(</span><span class="ne">OverflowError</span><span class="p">,</span> <span class="ne">ValueError</span><span class="p">)</span> <span class="k">as</span> <span class="n">exc</span><span class="p">:</span>
            <span class="n">exc_type</span> <span class="o">=</span> <span class="nb">type</span><span class="p">(</span><span class="n">exc</span><span class="p">)</span>
            <span class="n">exc_value</span> <span class="o">=</span> <span class="n">exc_type</span><span class="p">(</span>
                    <span class="s">&quot;Unsupported value: </span><span class="si">%r</span><span class="s">. You should install pytz.&quot;</span> <span class="o">%</span> <span class="n">dt</span><span class="p">)</span>
            <span class="n">exc_value</span><span class="o">.</span><span class="n">__cause__</span> <span class="o">=</span> <span class="n">exc</span>
            <span class="n">six</span><span class="o">.</span><span class="n">reraise</span><span class="p">(</span><span class="n">exc_type</span><span class="p">,</span> <span class="n">exc_value</span><span class="p">,</span> <span class="n">sys</span><span class="o">.</span><span class="n">exc_info</span><span class="p">()[</span><span class="mi">2</span><span class="p">])</span>

<span class="n">utc</span> <span class="o">=</span> <span class="n">pytz</span><span class="o">.</span><span class="n">utc</span> <span class="k">if</span> <span class="n">pytz</span> <span class="k">else</span> <span class="n">UTC</span><span class="p">()</span>
<span class="sd">&quot;&quot;&quot;UTC time zone as a tzinfo instance.&quot;&quot;&quot;</span>

<span class="c"># In order to avoid accessing the settings at compile time,</span>
<span class="c"># wrap the expression in a function and cache the result.</span>
<span class="n">_localtime</span> <span class="o">=</span> <span class="bp">None</span>

<div class="viewcode-block" id="get_default_timezone"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.get_default_timezone">[docs]</a><span class="k">def</span> <span class="nf">get_default_timezone</span><span class="p">():</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Returns the default time zone as a tzinfo instance.</span>

<span class="sd">    This is the time zone defined by settings.TIME_ZONE.</span>

<span class="sd">    See also :func:`get_current_timezone`.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">global</span> <span class="n">_localtime</span>
    <span class="k">if</span> <span class="n">_localtime</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span>
        <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">settings</span><span class="o">.</span><span class="n">TIME_ZONE</span><span class="p">,</span> <span class="n">six</span><span class="o">.</span><span class="n">string_types</span><span class="p">)</span> <span class="ow">and</span> <span class="n">pytz</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">None</span><span class="p">:</span>
            <span class="n">_localtime</span> <span class="o">=</span> <span class="n">pytz</span><span class="o">.</span><span class="n">timezone</span><span class="p">(</span><span class="n">settings</span><span class="o">.</span><span class="n">TIME_ZONE</span><span class="p">)</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="c"># This relies on os.environ[&#39;TZ&#39;] being set to settings.TIME_ZONE.</span>
            <span class="n">_localtime</span> <span class="o">=</span> <span class="n">LocalTimezone</span><span class="p">()</span>
    <span class="k">return</span> <span class="n">_localtime</span>

<span class="c"># This function exists for consistency with get_current_timezone_name</span></div>
<div class="viewcode-block" id="get_default_timezone_name"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.get_default_timezone_name">[docs]</a><span class="k">def</span> <span class="nf">get_default_timezone_name</span><span class="p">():</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Returns the name of the default time zone.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">return</span> <span class="n">_get_timezone_name</span><span class="p">(</span><span class="n">get_default_timezone</span><span class="p">())</span>
</div>
<span class="n">_active</span> <span class="o">=</span> <span class="n">local</span><span class="p">()</span>

<div class="viewcode-block" id="get_current_timezone"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.get_current_timezone">[docs]</a><span class="k">def</span> <span class="nf">get_current_timezone</span><span class="p">():</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Returns the currently active time zone as a tzinfo instance.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">return</span> <span class="nb">getattr</span><span class="p">(</span><span class="n">_active</span><span class="p">,</span> <span class="s">&quot;value&quot;</span><span class="p">,</span> <span class="n">get_default_timezone</span><span class="p">())</span>
</div>
<div class="viewcode-block" id="get_current_timezone_name"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.get_current_timezone_name">[docs]</a><span class="k">def</span> <span class="nf">get_current_timezone_name</span><span class="p">():</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Returns the name of the currently active time zone.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">return</span> <span class="n">_get_timezone_name</span><span class="p">(</span><span class="n">get_current_timezone</span><span class="p">())</span>
</div>
<span class="k">def</span> <span class="nf">_get_timezone_name</span><span class="p">(</span><span class="n">timezone</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Returns the name of ``timezone``.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">try</span><span class="p">:</span>
        <span class="c"># for pytz timezones</span>
        <span class="k">return</span> <span class="n">timezone</span><span class="o">.</span><span class="n">zone</span>
    <span class="k">except</span> <span class="ne">AttributeError</span><span class="p">:</span>
        <span class="c"># for regular tzinfo objects</span>
        <span class="k">return</span> <span class="n">timezone</span><span class="o">.</span><span class="n">tzname</span><span class="p">(</span><span class="bp">None</span><span class="p">)</span>

<span class="c"># Timezone selection functions.</span>

<span class="c"># These functions don&#39;t change os.environ[&#39;TZ&#39;] and call time.tzset()</span>
<span class="c"># because it isn&#39;t thread safe.</span>

<div class="viewcode-block" id="activate"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.activate">[docs]</a><span class="k">def</span> <span class="nf">activate</span><span class="p">(</span><span class="n">timezone</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Sets the time zone for the current thread.</span>

<span class="sd">    The ``timezone`` argument must be an instance of a tzinfo subclass or a</span>
<span class="sd">    time zone name. If it is a time zone name, pytz is required.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">if</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">timezone</span><span class="p">,</span> <span class="n">tzinfo</span><span class="p">):</span>
        <span class="n">_active</span><span class="o">.</span><span class="n">value</span> <span class="o">=</span> <span class="n">timezone</span>
    <span class="k">elif</span> <span class="nb">isinstance</span><span class="p">(</span><span class="n">timezone</span><span class="p">,</span> <span class="n">six</span><span class="o">.</span><span class="n">string_types</span><span class="p">)</span> <span class="ow">and</span> <span class="n">pytz</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">None</span><span class="p">:</span>
        <span class="n">_active</span><span class="o">.</span><span class="n">value</span> <span class="o">=</span> <span class="n">pytz</span><span class="o">.</span><span class="n">timezone</span><span class="p">(</span><span class="n">timezone</span><span class="p">)</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="k">raise</span> <span class="ne">ValueError</span><span class="p">(</span><span class="s">&quot;Invalid timezone: </span><span class="si">%r</span><span class="s">&quot;</span> <span class="o">%</span> <span class="n">timezone</span><span class="p">)</span>
</div>
<div class="viewcode-block" id="deactivate"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.deactivate">[docs]</a><span class="k">def</span> <span class="nf">deactivate</span><span class="p">():</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Unsets the time zone for the current thread.</span>

<span class="sd">    Django will then use the time zone defined by settings.TIME_ZONE.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">_active</span><span class="p">,</span> <span class="s">&quot;value&quot;</span><span class="p">):</span>
        <span class="k">del</span> <span class="n">_active</span><span class="o">.</span><span class="n">value</span>
</div>
<div class="viewcode-block" id="override"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.override">[docs]</a><span class="k">class</span> <span class="nc">override</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Temporarily set the time zone for the current thread.</span>

<span class="sd">    This is a context manager that uses ``~django.utils.timezone.activate()``</span>
<span class="sd">    to set the timezone on entry, and restores the previously active timezone</span>
<span class="sd">    on exit.</span>

<span class="sd">    The ``timezone`` argument must be an instance of a ``tzinfo`` subclass, a</span>
<span class="sd">    time zone name, or ``None``. If is it a time zone name, pytz is required.</span>
<span class="sd">    If it is ``None``, Django enables the default time zone.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">def</span> <span class="nf">__init__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">timezone</span><span class="p">):</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">timezone</span> <span class="o">=</span> <span class="n">timezone</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">old_timezone</span> <span class="o">=</span> <span class="nb">getattr</span><span class="p">(</span><span class="n">_active</span><span class="p">,</span> <span class="s">&#39;value&#39;</span><span class="p">,</span> <span class="bp">None</span><span class="p">)</span>

    <span class="k">def</span> <span class="nf">__enter__</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">timezone</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span>
            <span class="n">deactivate</span><span class="p">()</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="n">activate</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">timezone</span><span class="p">)</span>

    <span class="k">def</span> <span class="nf">__exit__</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">exc_type</span><span class="p">,</span> <span class="n">exc_value</span><span class="p">,</span> <span class="n">traceback</span><span class="p">):</span>
        <span class="k">if</span> <span class="bp">self</span><span class="o">.</span><span class="n">old_timezone</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span>
            <span class="n">deactivate</span><span class="p">()</span>
        <span class="k">else</span><span class="p">:</span>
            <span class="n">_active</span><span class="o">.</span><span class="n">value</span> <span class="o">=</span> <span class="bp">self</span><span class="o">.</span><span class="n">old_timezone</span>


<span class="c"># Templates</span>
</div>
<span class="k">def</span> <span class="nf">template_localtime</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">use_tz</span><span class="o">=</span><span class="bp">None</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Checks if value is a datetime and converts it to local time if necessary.</span>

<span class="sd">    If use_tz is provided and is not None, that will force the value to</span>
<span class="sd">    be converted (or not), overriding the value of settings.USE_TZ.</span>

<span class="sd">    This function is designed for use by the template engine.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="n">should_convert</span> <span class="o">=</span> <span class="p">(</span><span class="nb">isinstance</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">datetime</span><span class="p">)</span>
        <span class="ow">and</span> <span class="p">(</span><span class="n">settings</span><span class="o">.</span><span class="n">USE_TZ</span> <span class="k">if</span> <span class="n">use_tz</span> <span class="ow">is</span> <span class="bp">None</span> <span class="k">else</span> <span class="n">use_tz</span><span class="p">)</span>
        <span class="ow">and</span> <span class="ow">not</span> <span class="n">is_naive</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
        <span class="ow">and</span> <span class="nb">getattr</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="s">&#39;convert_to_local_time&#39;</span><span class="p">,</span> <span class="bp">True</span><span class="p">))</span>
    <span class="k">return</span> <span class="n">localtime</span><span class="p">(</span><span class="n">value</span><span class="p">)</span> <span class="k">if</span> <span class="n">should_convert</span> <span class="k">else</span> <span class="n">value</span>


<span class="c"># Utilities</span>

<div class="viewcode-block" id="localtime"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.localtime">[docs]</a><span class="k">def</span> <span class="nf">localtime</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">timezone</span><span class="o">=</span><span class="bp">None</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Converts an aware datetime.datetime to local time.</span>

<span class="sd">    Local time is defined by the current time zone, unless another time zone</span>
<span class="sd">    is specified.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">if</span> <span class="n">timezone</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span>
        <span class="n">timezone</span> <span class="o">=</span> <span class="n">get_current_timezone</span><span class="p">()</span>
    <span class="n">value</span> <span class="o">=</span> <span class="n">value</span><span class="o">.</span><span class="n">astimezone</span><span class="p">(</span><span class="n">timezone</span><span class="p">)</span>
    <span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">timezone</span><span class="p">,</span> <span class="s">&#39;normalize&#39;</span><span class="p">):</span>
        <span class="c"># available for pytz time zones</span>
        <span class="n">value</span> <span class="o">=</span> <span class="n">timezone</span><span class="o">.</span><span class="n">normalize</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
    <span class="k">return</span> <span class="n">value</span>
</div>
<div class="viewcode-block" id="now"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.now">[docs]</a><span class="k">def</span> <span class="nf">now</span><span class="p">():</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Returns an aware or naive datetime.datetime, depending on settings.USE_TZ.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">if</span> <span class="n">settings</span><span class="o">.</span><span class="n">USE_TZ</span><span class="p">:</span>
        <span class="c"># timeit shows that datetime.now(tz=utc) is 24% slower</span>
        <span class="k">return</span> <span class="n">datetime</span><span class="o">.</span><span class="n">utcnow</span><span class="p">()</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="n">tzinfo</span><span class="o">=</span><span class="n">utc</span><span class="p">)</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="k">return</span> <span class="n">datetime</span><span class="o">.</span><span class="n">now</span><span class="p">()</span>

<span class="c"># By design, these four functions don&#39;t perform any checks on their arguments.</span>
<span class="c"># The caller should ensure that they don&#39;t receive an invalid value like None.</span>
</div>
<div class="viewcode-block" id="is_aware"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.is_aware">[docs]</a><span class="k">def</span> <span class="nf">is_aware</span><span class="p">(</span><span class="n">value</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Determines if a given datetime.datetime is aware.</span>

<span class="sd">    The logic is described in Python&#39;s docs:</span>
<span class="sd">    http://docs.python.org/library/datetime.html#datetime.tzinfo</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">return</span> <span class="n">value</span><span class="o">.</span><span class="n">tzinfo</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">None</span> <span class="ow">and</span> <span class="n">value</span><span class="o">.</span><span class="n">tzinfo</span><span class="o">.</span><span class="n">utcoffset</span><span class="p">(</span><span class="n">value</span><span class="p">)</span> <span class="ow">is</span> <span class="ow">not</span> <span class="bp">None</span>
</div>
<div class="viewcode-block" id="is_naive"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.is_naive">[docs]</a><span class="k">def</span> <span class="nf">is_naive</span><span class="p">(</span><span class="n">value</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Determines if a given datetime.datetime is naive.</span>

<span class="sd">    The logic is described in Python&#39;s docs:</span>
<span class="sd">    http://docs.python.org/library/datetime.html#datetime.tzinfo</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">return</span> <span class="n">value</span><span class="o">.</span><span class="n">tzinfo</span> <span class="ow">is</span> <span class="bp">None</span> <span class="ow">or</span> <span class="n">value</span><span class="o">.</span><span class="n">tzinfo</span><span class="o">.</span><span class="n">utcoffset</span><span class="p">(</span><span class="n">value</span><span class="p">)</span> <span class="ow">is</span> <span class="bp">None</span>
</div>
<div class="viewcode-block" id="make_aware"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.make_aware">[docs]</a><span class="k">def</span> <span class="nf">make_aware</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">timezone</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Makes a naive datetime.datetime in a given time zone aware.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">timezone</span><span class="p">,</span> <span class="s">&#39;localize&#39;</span><span class="p">):</span>
        <span class="c"># available for pytz time zones</span>
        <span class="k">return</span> <span class="n">timezone</span><span class="o">.</span><span class="n">localize</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">is_dst</span><span class="o">=</span><span class="bp">None</span><span class="p">)</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="c"># may be wrong around DST changes</span>
        <span class="k">return</span> <span class="n">value</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="n">tzinfo</span><span class="o">=</span><span class="n">timezone</span><span class="p">)</span>
</div>
<div class="viewcode-block" id="make_naive"><a class="viewcode-back" href="../../../ref/utils.html#django.utils.timezone.make_naive">[docs]</a><span class="k">def</span> <span class="nf">make_naive</span><span class="p">(</span><span class="n">value</span><span class="p">,</span> <span class="n">timezone</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;</span>
<span class="sd">    Makes an aware datetime.datetime naive in a given time zone.</span>
<span class="sd">    &quot;&quot;&quot;</span>
    <span class="n">value</span> <span class="o">=</span> <span class="n">value</span><span class="o">.</span><span class="n">astimezone</span><span class="p">(</span><span class="n">timezone</span><span class="p">)</span>
    <span class="k">if</span> <span class="nb">hasattr</span><span class="p">(</span><span class="n">timezone</span><span class="p">,</span> <span class="s">&#39;normalize&#39;</span><span class="p">):</span>
        <span class="c"># available for pytz time zones</span>
        <span class="n">value</span> <span class="o">=</span> <span class="n">timezone</span><span class="o">.</span><span class="n">normalize</span><span class="p">(</span><span class="n">value</span><span class="p">)</span>
    <span class="k">return</span> <span class="n">value</span><span class="o">.</span><span class="n">replace</span><span class="p">(</span><span class="n">tzinfo</span><span class="o">=</span><span class="bp">None</span><span class="p">)</span></div>
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