Instant, a standard type

One moment in time, the same everywhere in the world: 2026-10-25T09:30:00Z.

Use it for when something happened, such as when an order was placed. For a day on a calendar, use CalendarDate. For a time on someone's clock in a place, use ZonedTime. For a time with no place yet, use LocalDateTime.

Shape

One value, with no fields to fill in. As text it reads 2026-10-25T09:30:00.250Z.

Example

example

Instant("2026-10-25T09:30:00Z")

text.parse(raw, as: Instant) reads one from text that comes from outside. Text that isn't one at all fails malformed, such as 2026-10-25, 2026-10-25T09:30:00 or yesterday.

This operation gives one: temporal.instant.

Good to know

It is always in UTC, written with Z. An offset such as +01:00 is refused.
clock.now gives the current one. Adding a Duration gives another: clock.now + 14d.
text.format needs a zone and a format, since a moment looks different in each place.
== tells you whether two are the same, and < and list.sort_by compare and sort them.

In JSON

A string, in a request, a response or json.write:

json

"2026-03-29T00:30:00Z""2026-10-25T09:30:00.250Z"

Details

Text form, storage, how it is shown, and operations

Instant is in the group Time and calendar, and has been in Jadpo since 0.1.0.

Text form

text.from writes one standard text form, the same form text.parse reads back: 2026-03-29T00:30:00Z and 2026-10-25T09:30:00.250Z.

How it is stored

It is stored in one column named for the field, of type timestamptz(3). 2026-10-25T09:30:00.250Z is stored as '2026-10-25 09:30:00.250000+00'::timestamptz.

How it is shown to people

text.format(value, locale:) shows it to people in their locale. A call also gives zone: and format:.

With locale: Locale.en_gb, zone: Zone.europe_london and format: TimeFormat.date_time_medium:

Value	Shown
`2026-03-29T00:30:00Z`	`29 Mar 2026, 00:30:00`
`2026-10-25T09:30:00.250Z`	`25 Oct 2026, 09:30:00`

Operations

temporal.between(start: Instant, end: Instant) -> Duration: How long from start to end: end - start.
temporal.format_relative(value: T, now: Instant, zone: Zone?, locale: Locale) -> PresentationText: value shown to a person in locale as how long ago it was from now: "just now", minutes, "Today at", "Yesterday at", the weekday, then the long date.
temporal.in_zone(instant: Instant, zone: Zone) -> ZonedTime: instant as the local time in zone.
temporal.instant(value: ZonedTime) -> Instant: The instant a local time is.
temporal.occurrences(rule: RecurrenceRule, from: T, count: Int) -> List<ZonedTime>: The next count occurrences of rule at or after from, in its zone (RFC 5545): fewer when the rule ends first; count is from 1 to 1000, so an unbounded rule is never expanded without a bound. From a date, the days they fall on, List<CalendarDate>, which a rule on dates gives; from an Instant, a timed rule's local times.
temporal.open_at(hours: OpeningHours, at: Instant) -> Bool: Whether hours are open at at, by the clock in their zone.

It also takes text.parse, text.from, text.format, json.read, json.write and ==. How every standard type behaves says how they work.