Date Helpers

Utility functions for working with date operations.

Functions

Function	Description
`add / subtract (date arithmetic)`	native JS `Temporal.PlainDate.prototype.add(duration) / .subtract(duration)` (Temporal (Stage 3))
`addDays`	Adds days to a date.
`addMonths`	Adds months to a date.
`addYears`	Adds years to a date.
`clampDate`	Clamps a date to a [min, max] range.
`compare`	Comparison of two dates.
`compare (ordering)`	native JS `Temporal.PlainDate.compare(a, b) / Temporal.Instant.compare(a, b)` (Temporal (Stage 3))
`dateToISOString`	Formats a date to ISO string or returns null.
`daysDifference`	Gets the difference in days between two dates.
`daysInMonth`	Returns the number of days in the given month of the given year.
`difference`	Calculates the difference between two dates in the specified unit.
`eachDay`	Returns an array of `Date` objects for each day from `start` to `end` (inclusive).
`eachMonth`	Returns an array of `Date` objects for the first day of each month from `start` to `end` (inclusive).
`endOf`	Returns a new `Date` set to the end of the given unit.
`ensureDate`	Safely converts a date-like value to a valid `Date` object, or returns `null`.
`formatDuration`	Formats a duration in milliseconds as a compact human-readable string.
`formatInTimezone`	Formats a date in a specific IANA timezone using `Intl.DateTimeFormat`.
`from (parse temporal string)`	native JS `Temporal.Instant.from(str) / Temporal.PlainDate.from(str) / etc.` (Temporal (Stage 3))
`fromMillis`	Creates a `Date` from a timestamp in milliseconds.
`fromSeconds`	Creates a `Date` from a timestamp in seconds.
`getTimezoneOffset`	Returns the UTC offset in minutes for the given IANA timezone at a specific point in time.
`isBusinessDay`	Checks whether a date falls on a business day (i.e.
`isLeapYear`	Returns `true` if the given year is a leap year.
`isSameDay`	Checks if two dates are the same day.
`isSameMonth`	Checks if two dates are in the same month (and year).
`isSameYear`	Checks if two dates are in the same year.
`isTimestampInSeconds`	Checks if a timestamp is likely in seconds (Java/Unix style) vs milliseconds (JavaScript style)
`isValidDateString`	Checks whether a string can be parsed into a valid `Date`.
`isWeekend`	Checks whether a date falls on a weekend day.
`isWithinRange`	Checks whether a date falls within a range (inclusive on both ends).
`listTimezones`	Returns the list of IANA timezone identifiers supported by the runtime.
`normalizeTimestamp`	Converts a timestamp to JavaScript milliseconds format
`now (date/time/instant)`	native JS `Temporal.Now.instant() / .zonedDateTimeISO() / .plainDateISO() / .plainTimeISO()` (Temporal (Stage 3))
`overlaps`	Checks whether two date ranges overlap.
`safeDate`	Safely creates a Date object from various input types.
`startOf`	Returns a new `Date` set to the start of the given unit.
`timeAgo`	Formats a date as a human-readable relative time string.
`toISO8601`	Converts a date to ISO 8601 format Format: YYYY-MM-DDTHH:mm:ss.sssZ
`toMillis`	Converts a date to a timestamp in milliseconds (epoch millis).
`toPlainDate / toPlainDateTime / toPlainTime`	native JS `Temporal.ZonedDateTime.prototype.toPlainDate() / toPlainDateTime() / toPlainTime()` (Temporal (Stage 3))
`toRFC2822`	Converts a date to RFC 2822 format Format: Day, DD Mon YYYY HH:mm:ss +0000 Used in email headers (Date field) and HTT…
`toRFC3339`	Converts a date to RFC 3339 format Format: YYYY-MM-DDTHH:mm:ssZ or YYYY-MM-DDTHH:mm:ss+HH:mm RFC 3339 is a profile of…
`toSeconds`	Converts a date to a timestamp in seconds (epoch seconds).
`toTemporalInstant`	native JS `Date.prototype.toTemporalInstant()` (Temporal (Stage 3))
`toZonedDateTime`	native JS `Temporal.Instant.prototype.toZonedDateTimeISO(tz)` (Temporal (Stage 3))
`until / since (difference)`	native JS `Temporal.PlainDate.prototype.until(other) / .since(other)` (Temporal (Stage 3))
`WeekDays`	Named day-of-week constants following the JavaScript `Date.getDay()` convention.