Choose a start and end date to see results immediately. Use Swap dates to exchange the inputs. Reversed dates produce a positive result. The default counts elapsed days; enable the include option to count both dates.
October 1 to October 3, 2026 is 2 days, or 3 days including both dates. January 1 to October 13, 2026 is 285 days, 40 weeks and 5 days, or 0 years, 9 months and 12 days.
The elapsed interval is 0 days. Including both start and end dates gives 1 day.
We first find the maximum whole months that can be added to the earlier date, then count remaining days. Whole months are divided by 12 to show years. If the original day does not exist in the target month, we use its last day. Each addition uses the original date to prevent drift. January 31 to March 1, 2026 is 29 days, or 0 years, 1 month and 1 day. February 29 in leap years is respected.
Including both dates uses the day after the later date as the exclusive end, adding one day consistently to all representations. These are calendar dates without times: DST and device time zones do not affect results. Weekends and holidays are counted; this is not a business day calculator.