de>x</code> containing the
date. This column should either be in <code>Date</code> format or convertible to
<code>Date</code> format with <code><a href="https://rdrr.io/r/base/as.Date.html" class="external-link">as.Date()</a></code>.</p></dd>


<dt id="arg-site-vars">site_vars<a class="anchor" aria-label="anchor" href="#arg-site-vars"></a></dt>
<dd><p>character; names of one of more columns in <code>x</code> that define a
site, typically the location (e.g. latitude/longitude) and observer ID.</p></dd>


<dt