How to use
Pick a date, choose add or subtract, and enter the number of days, weeks, months or years. You’ll see the resulting date with its day of the week and the difference in days.
“Business days” skip Saturdays and Sundays — handy for deadlines like “within 10 business days”. Public holidays are not taken into account.
How months and years are added
Months have different lengths, so the day of the month is kept, and if that day doesn’t exist in the target month, the last day of the month is used: January 31 + 1 month = February 28 (February 29 in a leap year).
Years work the same way: February 29, 2024 + 1 year = February 28, 2025.
Examples
- October 19, 2026 + 90 days = Sunday, January 17, 2027.
- October 19, 2026 − 6 months = April 19, 2026.
- January 31, 2026 + 1 month = February 28, 2026.
FAQ
Is the start date counted? No: “1 day after” October 19 is October 20.
How do I count business days? This calculator counts calendar days. To find the number of weekdays in a period, use the days calculator.