Date Calculator
Add or subtract days and months, or count the days between two dates.
Adding a month keeps the day where it exists and clamps where it does not, so 31 January plus one month is 28 February.
A date on the calendar is not a plan.
Knowing the deadline is the easy part. PomoTodo turns it into tasks with time behind them, so you can see whether the work actually fits before the date arrives rather than after.
Free plan tracks unlimited focus time across unlimited tasks. No card required.
Two questions come up constantly and neither is comfortable to do in your head. What is the date ninety days from now, and how many days are there between these two dates.
Both get fumbled for the same reason. Months are not the same length, leap years move everything by a day, and counting on your fingers across a year boundary is how people end up a day out on a contract.
Add or subtract years, months and days in one go and the result comes back as a full date with the day of the week attached. Switch to the second mode and you get the gap between two dates in days, in calendar years and months, and in hours.
More tools
Exact age in years, months and days, plus the next birthday.
Working days between dates, or when a deadline lands.
Weeks from a date, weeks between dates, and week numbers.
Days, hours and minutes until whatever you are waiting for.
Questions
How do I add days to a date?
Pick the start date, choose add, and type the number of days. Years, months and days can all be used at once, and the result appears as a full date including the day of the week.
How many days are between two dates?
Switch to the days between mode and pick both dates. You get the total in days, the same gap expressed in calendar years, months and days, and the equivalent in hours.
What happens when I add a month to the 31st?
The day is kept where it exists and clamped where it does not, so 31 January plus one month is 28 February, or 29 February in a leap year. This is how calendar apps behave and it keeps repeated additions predictable.
Are leap years handled?
Yes. Every count runs on real calendar dates, so 29 February is included whenever it falls inside the range and the century rule is applied correctly.