Time & dates
Date calculator
Enter a start date and a number of days to add — or a negative number to subtract — to find the resulting date and day of the week.
How to calculate it
This calculator moves forward or backward from a date by a whole number of days. Enter a positive number to count forward, such as 45 days from today, or a negative number to count backward, such as 14 days before a deadline. The result shows the resulting calendar date and its day of the week. This is the reverse of the days between dates calculator, which starts with two dates and counts the days between them.
Worked examples
| Example | Working | Answer |
|---|---|---|
| 5 days from 1 Jan 2026 | 1 Jan 2026 + 5 | Tue 6 Jan 2026 |
| 30 days from 1 Jan 2026 | 1 Jan 2026 + 30 | Sat 31 Jan 2026 |
| 90 days from 1 Jan 2026 | 1 Jan 2026 + 90 | Wed 1 Apr 2026 |
| 14 days before 1 Feb 2026 | 1 Feb 2026 − 14 | Sun 18 Jan 2026 |
| 365 days from 1 Mar 2026 | 1 Mar 2026 + 365 | Mon 1 Mar 2027 |
| 100 days from 1 Jan 2026 | 1 Jan 2026 + 100 | Sat 11 Apr 2026 |
Frequently asked questions
How do I count backward from a date?
Enter a negative number of days. For example, entering −14 with a start date of 1 February finds the date 14 days before it.
Does this account for leap years?
Yes. February 29 is counted like any other day in a leap year, so a span of days that crosses it lands on the correct date automatically.
Can I find out what day of the week a date falls on?
Yes. Enter 0 as the number of days, and the result shows the day of the week for your start date.
How is this different from the days between dates calculator?
This tool starts with one date and a number of days, and finds the resulting date. The days between dates calculator does the opposite: it starts with two dates and counts the days between them.
Do daylight-saving changes affect the result?
No. Dates are calculated at UTC midnight, so clock changes cannot shift the resulting calendar date.
Method: standard arithmetic. Examples are illustrative. How our calculators work.