Is Before

This indicates whether the Day.js object is before the other supplied date-time.

dayjs().isBefore(dayjs('2011-01-01')); // default milliseconds

If you want to limit the granularity to a unit other than milliseconds, pass it as the second parameter. In that case, the comparison respects the given unit and the units above.

dayjs().isBefore('2011-01-01', 'month'); // compares month and year

Units are case insensitive, and support plural and short forms.

List of all available units