eachQuarterOfInterval
Get all quarters in an interval as ZonedDateTime array
Returns an array of ZonedDateTime objects for each quarter within the interval. Each element represents the first moment of the quarter (1st day of the quarter's starting month at midnight). The interval is inclusive of both start and end quarters. Quarters: Q1 = Jan–Mar, Q2 = Apr–Jun, Q3 = Jul–Sep, Q4 = Oct–Dec.
Signature
function eachQuarterOfInterval(interval: {
start: Temporal.Instant | Temporal.ZonedDateTime;
end: Temporal.Instant | Temporal.ZonedDateTime;
}): Temporal.ZonedDateTime[]
function eachQuarterOfInterval(interval: {
start: Temporal.PlainDate;
end: Temporal.PlainDate;
}): Temporal.PlainDate[]Input type determines output type: a PlainDate interval needs no timezone and returns PlainDate[] (the first day of each quarter).
Parameters
| Parameter | Type | Description |
|---|---|---|
interval | { start, end } | The interval with start and end datetimes |
Returns
Array of Temporal.ZonedDateTime at the start of each quarter in the interval.
For Instant inputs, UTC is used as the timezone. For ZonedDateTime inputs, the timezone of the start date is preserved.
Examples
Basic usage
import { eachQuarterOfInterval } from '@gobrand/tiempo';
const start = Temporal.ZonedDateTime.from('2025-02-15T10:00:00Z[UTC]');
const end = Temporal.ZonedDateTime.from('2025-11-20T14:00:00Z[UTC]');
const quarters = eachQuarterOfInterval({ start, end });
// [
// 2025-01-01T00:00:00Z[UTC], // Q1
// 2025-04-01T00:00:00Z[UTC], // Q2
// 2025-07-01T00:00:00Z[UTC], // Q3
// 2025-10-01T00:00:00Z[UTC] // Q4
// ]Cross-year boundary
const start = Temporal.ZonedDateTime.from('2024-11-15T00:00:00Z[UTC]');
const end = Temporal.ZonedDateTime.from('2025-05-15T00:00:00Z[UTC]');
const quarters = eachQuarterOfInterval({ start, end });
// [
// 2024-10-01T00:00:00Z[UTC], // Q4 2024
// 2025-01-01T00:00:00Z[UTC], // Q1 2025
// 2025-04-01T00:00:00Z[UTC] // Q2 2025
// ]From PlainDate (no timezone)
const quarters = eachQuarterOfInterval({
start: Temporal.PlainDate.from('2025-02-15'),
end: Temporal.PlainDate.from('2025-08-20'),
});
// [2025-01-01, 2025-04-01, 2025-07-01] (PlainDate[])Common Patterns
Build quarterly reporting periods
import { eachQuarterOfInterval, addQuarters } from '@gobrand/tiempo';
function getQuarterlyPeriods(
fiscalStart: Temporal.ZonedDateTime,
fiscalEnd: Temporal.ZonedDateTime
) {
return eachQuarterOfInterval({ start: fiscalStart, end: fiscalEnd }).map(quarterStart => ({
periodStart: quarterStart,
periodEnd: addQuarters(quarterStart, 1).subtract({ nanoseconds: 1 })
}));
}