isDateString

Checks if the given value is a valid date string.

`isDateString()`

Checks if the given value is a valid date string.

Note

A value is considered a valid date string if it is a string and can be parsed by Date.parse().
This uses the native JavaScript date parser internally.

static isDateString(value: unknown): value is string

boolean - Whether valid date string

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Last updated: Thu, May 21, 2026 07:12:18AM (UTC)

getDatesForDay

Returns ISO date strings or Chronos instances for each occurrence of a weekday.

isLeapYear

Checks if the year in the date string or year (from 0 - 9999) is a leap year.