startOfUtc

Signature

startOfUtc(value: string, unit: any, options?: { weekStartsOn?: "monday" | "sunday"; fractionalSecondDigits?: FractionalDigit; }): string

import { startOfUtc } from "@northguild/gmt/utc/calculate";

Return the start of the specified date-time unit for a given UTC datetime string.

• Converts to ZonedDateTime, sets to start of unit, converts back to Instant.
• Supports: “year”, “month”, “week”, “day”, “hour”, “minute”, “second”, “millisecond”, “microsecond”, “nanosecond”.
• Returns “” for invalid input.

Parameters

Parameter	Type	Description
value	string	ISO UTC datetime string
unit	any	Temporal.DateUnit | Temporal.TimeUnit to specify the start

Options

options

Option	Type	Default
weekStartsOn?	"monday" | "sunday"	—
fractionalSecondDigits?	FractionalDigit	—

Returns

UTC Instant string representing the start of the unit, or “” on invalid input

Related types

• FractionalDigit

Examples

startOfUtc("2024-03-15T14:30:45Z", "year") // "2024-01-01T00:00:00Z"
startOfUtc("2024-03-15T14:30:45Z", "month") // "2024-03-01T00:00:00Z"
startOfUtc("invalid", "year") // ""

Source

utc/calculate/startOfUtc.ts