Date Calculator
Calculate days, weeks, and months between two dates
Enter Dates
End date must be after start date.
Quick Calculate
Common Use Cases
- Days until anniversary or birthday (D-Day)
- Project duration or days until deadline
- Trip length or event preparation period
- Contract or warranty expiration date
When you need a date calculator
Counting days by hand sounds easy until you mix months of 30 and 31 days, leap years, and the question of whether the start date counts. The cases below are where this tool matters.
- D-Day and anniversaries — wedding anniversaries, "100 days together," due dates, time until an exam.
- Contracts and recurring payments — lease end, insurance and subscription renewals, warranty expiration. Reminders set in business days need an accurate weekday count.
- Projects and trips — sprints remaining until launch, business days until a vacation departure.
Why business-day counts differ
The working days only option excludes Saturdays and Sundays from the range. It uses the same convention as Excel NETWORKDAYS: the start date is counted, the end date is not. That is why a calendar-day span can differ from a business-day span. A seven-day window that contains one weekend has five business days, but seven days starting on Saturday and ending the following Friday yield only four. The starting day of the week matters.
Public holidays are not subtracted automatically. If you need a precise count, subtract local holidays yourself (for example, a US Thanksgiving Friday or a Korean Chuseok long weekend).
Frequently asked questions
Does it include weekends?
The default calculation includes Saturdays and Sundays. Toggle working days only to exclude weekends.
Are public holidays excluded automatically?
No. The tool does not have a holiday calendar. For accurate business-day counts in countries with major public holidays, subtract the holiday count from the result.
Can it handle lunar calendar dates?
Inputs are Gregorian dates only. Convert lunar anniversaries (for example, Korean lunar birthdays) to a Gregorian date first, then enter both ends.
Related tools
Once you have the date range, the tools below help with the rest of group scheduling.
Coordinate Dates with DateDate
Collect everyone's available dates at once. Start with just a link — no sign-up needed.
Create Schedule