Date Calculator

Calculate date differences, find dates after n days/weeks/months/years from a specified date, and count down from today to a target date.

Start Date

End Date

Include first day

Please enter a valid date.

How to Use

Switch calculation types with the buttons above and enter the required dates or numbers for automatic calculation.
"Date - Date" calculates the difference between two dates (days, weeks, months, years).
"Date + Days/Weeks/Months/Years" calculates the date n days/weeks/months/years after a specified date.
"Today to Target Date" counts the remaining days from today to a specified date.

Dates are calculated using the Gregorian calendar.
Months and years are estimated using average days (1 month = 30.4375 days, 1 year = 365.2425 days).
Leap years and monthly day differences are not fully considered.
We are not responsible for any damages arising from the use of this service.

When would you use this?
Birthday and anniversary countdowns, deadline/contract/subscription management, regular events, exam/graduation/test day counting, and many other uses.
What does "Include first day" mean?
Use this when you want to count the start date as day 1 (e.g., days since birth).
How are months and years calculated?
They are estimated using average days. For precise months/years, please check with a calendar.
Do you support Japanese or lunar calendars?
This tool only supports the Gregorian calendar.
Can individuals be identified from this information?
Date information alone cannot identify individuals.

This information is general content. Please also refer to official sites and specialized organizations for detailed information.