Temporal.ZonedDateTime.prototype.equals()
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The equals() method of Temporal.ZonedDateTime instances returns true if this date-time is equivalent in value to another date-time (in a form convertible by Temporal.ZonedDateTime.from()), and false otherwise. They are compared both by their instant values, time zones, and their calendars, so two date-times from different calendars or time zones may be considered equal by Temporal.ZonedDateTime.compare() but not by equals().
Syntax
equals(other)
Parameters
other-
A string, an object, or a
Temporal.ZonedDateTimeinstance representing the other date-time to compare. It is converted to aTemporal.ZonedDateTimeobject using the same algorithm asTemporal.ZonedDateTime.from().
Return value
true if this date-time is equal to other both in their instant value, time zone, and their calendar, false otherwise.
Note that the time zones are canonicalized before comparison, so if their time zone IDs are both named and identify the same time zone, then they would be considered the same even when the exact names may be aliases of each other. Offset identifiers are compared by the offset values they represent. Offset identifiers never compare equal to named identifiers even when the named identifier's time zone always uses that offset.
Examples
Using equals()
// Asia/Kolkata and Asia/Calcutta are aliases of each other
const dt1 = Temporal.ZonedDateTime.from(
"2021-07-01T12:34:56+05:30[Asia/Kolkata]",
);
const dt2 = Temporal.ZonedDateTime.from(
"2021-07-01T12:34:56+05:30[Asia/Calcutta]",
);
console.log(dt1.equals(dt2)); // true
const dt3 = Temporal.ZonedDateTime.from("2021-07-01T12:34:56+05:30[+05:30]");
console.log(dt1.equals(dt3)); // false
const dt4 = Temporal.ZonedDateTime.from(
"2021-07-01T12:34:56+05:30[Asia/Kolkata][u-ca=buddhist]",
);
console.log(dt1.equals(dt4)); // false
Testing if two time zone identifiers are equivalent
function sameTimeZone(timeZone1, timeZone2) {
const dt1 = Temporal.ZonedDateTime.from({
year: 2021,
month: 7,
day: 1,
timeZone: timeZone1,
});
const dt2 = Temporal.ZonedDateTime.from({
year: 2021,
month: 7,
day: 1,
timeZone: timeZone2,
});
return dt1.equals(dt2);
}
console.log(sameTimeZone("Asia/Kolkata", "Asia/Calcutta")); // true
console.log(sameTimeZone("Asia/Shanghai", "Asia/Taipei")); // false
Specifications
| Specification |
|---|
| Temporal # sec-temporal.zoneddatetime.prototype.equals |
Browser compatibility
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