sing the Gregorian calendar.
</p>
</dd>
<dt><a class="ref" href="isdatetime.html">isdatetime</a></dt>
<dd><p>True if input is a &rsquo;datetime&rsquo; array, false otherwise.
</p>
</dd>
<dt><a class="ref" href="NaT.html">NaT</a></dt>
<dd><p>“Not-a-Time”.
</p>
</dd>
<dt><a class="ref" href="calendarDuration.html">calendarDuration</a></dt>
<dd><p>Durations of time using variable-length calendar periods, such as days, months, and years, which may vary in length over time.
</p>
</dd>
<dt><a class="ref" href