Date Calculator
Find the date a number of days, weeks, months or years before or after any date — for due dates, deadlines, warranties, subscriptions and planning.
How to use the Date Calculator
- Choose the start date.
- Choose whether to add or subtract.
- Enter the years, months, weeks and days, then read the result.
How it works
Years and months are applied first on the calendar, then weeks and days are added as exact 24-hour days. When adding months lands on a date that does not exist — for example one month after 31 January — the result is moved to the last day of that month (28 or 29 February).
This matches how most contracts and billing systems count months. To count a fixed number of days instead, enter the whole period in the days field.
Useful periods in days
| Period | Days |
|---|---|
| 1 week | 7 |
| 2 weeks | 14 |
| 30 days | 30 |
| 90 days (≈ 3 months) | 90 |
| 6 months | 181–184 |
| 1 year | 365 or 366 |
| Pregnancy (40 weeks) | 280 |
Frequently asked questions
What date is 30 days from today?
Enter today’s date and add 30 days — the calculator shows the exact date and weekday.
What date is 90 days from now?
Add 90 days to today’s date. Note that 90 days is not always exactly 3 calendar months.
How does adding a month work at the end of the month?
If the day does not exist in the target month, the last day of that month is used — 31 January + 1 month = 28 February (29 in a leap year).
Can I subtract dates?
To find the number of days between two dates, use the days between dates calculator.