Utc

Utc adds methods to EsDay and esday to dates as UTC.

The utc method converts an EsDay instance to utc. If the optional parameter keepLocalTime is true, then the the local time is not changed.
The local method converts an EsDay instance from utc to the local timezone.
The isUTC method checks, if the EsDay instance in utc mode.
The utcOffset getter returns the offset to utc for the EsDay instance in minutes.
The utcOffset setter sets the offset to utc for the EsDay instance to the given value (minutes). If the optional parameter keepLocalTime is true, then the the local time is not changed (changing the point in Universal Time).

Usage

Dependencies

Utc has no dependencies on other plugins.

Method signatures

Methods added to EsDay instances:

esday().utc(keepLocalTime?: boolean): EsDay
esday().local(): EsDay
esday().isUTC(): boolean
esday().utcOffset(): number
esday().utcOffset(offset: number | string, keepLocalTime?: boolean): EsDay

parameter	description
offset	offset from utc
keepLocalTime	keep the existing time of day

If the first parameter of utcOffset is less than 16 and greater than -16, it will be interpreted as hours instead of minutes.

utcOffset will take a string as input value; EsDay will search the string for the last match of +00 -00 +00:00 +0000 -00:00 -0000 Z, so you can even pass an ISO8601 formatted string to offset and esday will set that UTC offset. If the string does not include 'Z', it must include the + or - character.

Methods added to esday:

esday.utc(date: DateType): EsDay

Examples

import { esday } from 'esday'
import utcPlugin from 'esday/plugins/utc'

esday.extend(utcPlugin)

esday('2025-01-06T12:34:56.789').utc()
// Returns esday for '2025-01-06T11:34:56Z' in utc mode
// when timezone offset on Jan 6 is '+01:00'

esday('2025-01-06T12:34:56.789').utc(true)
// Returns esday for '2025-01-06T12:34:56Z' in utc mode

esday.utc('2025-01-06T12:34:56.789')
// Returns esday for '2025-01-06T12:34:56Z' in utc mode

esday('2025-01-06T12:34:56.789').utc(true).local()
// Returns esday for '2025-01-06T13:34:56+01:00' in local mode,
// when timezone offset on Jan 6 is '+01:00'

esday('2025-01-06T12:34:56.789').utcOffset()
// Returns 60, when timezone offset on Jan 6 is '+01:00'

esday('2025-01-06T12:34:56.789').utc(true).utcOffset(120)
// Returns esday for '2025-01-06T13:34:56+02:00' in local mode

esday('2025-01-06T12:34:56.789').utc(true).utcOffset(120, true)
// Returns esday for '2025-01-06T11:34:56+02:00' in local mode,
// when timezone offset on Jan 6 is '+01:00'. utcOffset is 120.