s="op">=</span><span class="fu"><a href="https://rdrr.io/r/base/as.POSIXlt.html" class="external-link">as.POSIXct</a></span><span class="op">(</span><span class="st">"2021-06-30 23:55"</span><span class="op">)</span>, by<span class="op">=</span><span class="st">"5 min"</span> <span class="op">)</span></span>
<span><span class="va">ndt</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/length.html" class="external-link">length</a></span><span class="op">(</span><span class=