Calculate calendar dates without converting them to approximate month or year lengths. Add or subtract a duration, find the exact difference between dates, or count working days.
Date arithmetic runs on calendar dates in UTC, which prevents daylight-saving clock changes from creating unexpected 23-hour or 25-hour differences.
Years and months are applied before weeks and days. When the destination month is shorter, the day is clamped to the final valid day of that month. For example, adding one month to January 31 produces the last day of February.
Date difference reports both a calendar duration and exact elapsed days. Business day mode treats Monday through Friday as working days, supports inclusive or exclusive boundaries, and removes valid custom holiday dates that fall on weekdays.
All dates are calculated as calendar dates in UTC, which prevents daylight-saving clock changes from creating 23-hour or 25-hour day differences.
Related date calculations: Date Calculator · Days Between Dates · Add Days to Date · Business Days