rftime" class="binding-sym">os/strftime</span> <span class="binding-type">cfunction</span> <span class="binding-type"><a href="https://github.com/janet-lang/janet/blob/0d9e999/src/core/os.c#L1761">source</a></span> <pre class="binding-text">(os/strftime fmt &amp;opt time local)

Format the given time as a string, or the current time if `time` is not given. The time is formatted according to the same rules as the ISO C89 function strftime(). The time is formatted in UTC unless `local` is truthy, in which cas