The defined beginning of <a href="https://en.wikipedia.org/wiki/Unix_time" id="mwAmw" rel="mw:WikiLink" title="Unix time">Unix time</a>, at 00:00:00.<sup about="#mwt387" class="mw-ref reference" data-mw='{"name":"ref","attrs":{"name":"single-unix-spec-4.16"},"body":{"id":"mw-reference-text-cite_note-single-unix-spec-4.16-75"}}' id="cite_ref-single-unix-spec-4.16_75-0" rel="dc:references" typeof="mw:Extension/ref"><a href="./January_1#cite_note-single-unix-spec-4.16-75" id="mwAm0" style="counter-reset: mw-Ref 75;"><span class="mw-reflink-text" id="mwAm4">[75]</span></a></sup>