Add or subtract days, weeks, months, or years from a date to find the resulting date and its weekday. Enter the date and the change.
Usage Tip
Great for deadlines: add 30, 60, or 90 days to a start date to find the due date and the weekday it lands on.
Month and year shifts keep the same day number where possible
Month and year shifts keep the same day of the month, adjusting when the target month is shorter.
Month and year shifts follow standard calendar arithmetic.
Choose Subtract to go backward in time from the start date.
Adding time to a date is easy until months and years get involved, because months have different lengths and leap years add a day to February. This calculator adds or subtracts days, weeks, months, or years and gives the resulting date together with the day of the week.
When you add a month, the day number usually stays the same, but if the target month is shorter the date is adjusted to its last day. For example, one month after January 31 lands at the end of February. Adding years to February 29 in a non-leap year does the same. This is useful for deadlines, warranty expiry dates, and payment schedules.