Pick the start date
Today, a deadline, a birth date or any other.
Add or subtract days from a date
Pick a date and enter years, months, weeks and days to add or subtract. You get the resulting date, its weekday, its day of the year and its week number.
- Free
- No sign-up
- Runs in your browser
100% private — the calculation is done in your browser and nothing is sent to any server.
Next step
Keep going with your result in another tool. Nothing is uploaded.
How it works
Enter what to add or subtract
Years, months, weeks and days, together if you like.
Read the new date
With its weekday, day of the year and ISO week.
What date is 90 days from now?
Adding time to a date is a small job that turns up everywhere: a warranty that lasts 90 days, a trial period of two months, a notice period of four weeks, a payment due 30 days after an invoice, a course that ends 12 weeks after it starts or a baby due 40 weeks after a date. Counting on a calendar is slow and error-prone. Enter the start date and the amount to add or subtract, and the result appears with its weekday.
Years, months, weeks and days together
You can combine all four units in a single calculation, such as adding 1 year, 2 months and 10 days. The tool applies the years and months first, then the weeks and days, which is how people normally think of it. The operation can be an addition or a subtraction, so you can also find out what date was 100 days ago.
The end-of-month rule
Adding months has one subtle case. If you add one month to 31 January, there is no 31 February. The tool moves to the last day of the resulting month, so the answer is 28 February, or 29 in a leap year, which is what calendars and most contracts do. Adding years to 29 February follows the same rule and lands on 28 February in years that are not leap years.
More information about the date
Besides the new date, the tool tells you the day of the week, which matters if the deadline falls on a weekend, the day of the year, useful for ordinal dates and planning, and the ISO week number, used in many companies, schools and logistics systems, together with the number of calendar days from the original date.
What it does not do
The tool adds calendar days. It does not skip weekends or holidays, so for business-day deadlines use the business days calculator. It handles dates only, not times of day, and uses the Gregorian calendar throughout.
Frequently asked questions
How do I add days to a date?
Pick the start date, choose Add, and enter the number of days. The resulting date appears with its weekday.
How do I find what date it was 60 days ago?
Choose Subtract and enter 60 in Days. The tool counts backwards from the start date.
What happens when I add a month to the 31st?
The result is the last day of the next month if it has no 31st: 31 January plus one month is 28 (or 29) February.
Can I add weeks and months at the same time?
Yes. All four fields can be used together; the years and months are applied first, then the weeks and days.
Does it skip weekends?
No, it adds calendar days. To skip weekends and holidays, use the business days calculator.
Are my dates sent anywhere?
No. The calculation is done in your browser.
Related tools
More utilities that also run without leaving your browser.
Age calculatorExact age from a date of birth, and the days until the next birthday.
Business days calculatorCount working days between two dates, or add business days to a date.
Countdown timerA live countdown to a date and time, and a simple timer with a sound.
Days between two datesHow many days, weeks, months and years are there between two dates?
Time zone converterConvert a time between time zones and see it in up to four cities at once.
Meeting time finderFind hours when people in different time zones are all within their working day.