JavaScript Instant since()
Example
const start = Temporal.Instant.from("2026-05-16T14:30:00Z");
const end = Temporal.Instant.from("2026-05-17T14:30:00Z");
const duration = end.since(start, {smallestUnit:"hours"});
Try it Yourself »
Description
The since() method returns a duration object representing
the duration from another instant.
The since() method does not change the original instant.
Syntax
instant.since(other)
Parameters
| Parameter | Description |
| other | A PlainDate. |
| option | Any valid Temporal.Duration.round() option. |
Return Value
| Type | Description |
| Object | A duration object representing the duration since the other date. |
Browser Support
Temporal is a major update to the JavaScript standard (TC39).
It is currently supported in Chrome, Edge, Firefox, and Opera Safari has not shipped it yet.
| Chrome 144 |
Edge 144 |
Firefox 139 |
Safari |
Opera 128 |
| Jan 2026 | Jan 2026 | May 2025 | 🚫 | Feb 2026 |
The Safari implementation can be tested in Safari Technology Preview by enabling the --use-temporal runtime flag.
Polyfill
Until Safari supports Temporal natively, you can use the official polyfill:
<script
src="https://cdn.jsdelivr.net/npm/@js-temporal/polyfill@0.5.1/dist/index.umd.js">
</script>
