Returns the time origin — the start of the current navigation in browsers, or the process
start time in Node.js.
Prefers performance.timing.navigationStart over performance.timeOrigin because
timeOrigin can be much farther in the past than the actual navigation start (Firefox 71,
https://bugzilla.mozilla.org/show_bug.cgi?id=1429926) and is not supported in Safari <15.
Falls back to performance.timeOrigin in environments without performance.timing
(Web Workers, Service Workers, Node.js). performance.timeOrigin is fractional, so it is floored
to whole milliseconds, like navigationStart: the origin is never later than the actual one.
Returns the time origin — the start of the current navigation in browsers, or the process start time in Node.js.
Prefers
performance.timing.navigationStartoverperformance.timeOriginbecausetimeOrigincan be much farther in the past than the actual navigation start (Firefox 71, https://bugzilla.mozilla.org/show_bug.cgi?id=1429926) and is not supported in Safari <15. Falls back toperformance.timeOriginin environments withoutperformance.timing(Web Workers, Service Workers, Node.js).performance.timeOriginis fractional, so it is floored to whole milliseconds, likenavigationStart: the origin is never later than the actual one.