ClockA date, a little further along
Enter a starting date, choose add or subtract, and set whole numbers of years, months, and days. The tool combines the year and month changes first, then applies the days.
What happens at the end of a month?
If the original day is not in the target month, it is clamped to that month’s last day. For example, January 31 plus one month becomes February 28 in an ordinary year or February 29 in a leap year. Adding one year to February 29 becomes February 28.
This is calendar arithmetic using the proleptic Gregorian calendar. Public holidays and working-day rules are not applied; adding and subtracting months is not always reversible.