Convert tools

Date Difference Calculator

Count calendar days between two dates, with an option to include both endpoints. Leap years are handled automatically.

Convert in your browser · No sign-up

Uses Gregorian calendar dates at UTC midnight, avoiding daylight-saving changes. Inclusive mode requires the end date to be on or after the start.

Up to 100,000 UTF-16 units per input and 1,000,000 per result. See the supported formats and examples below.

How to use

  1. Count calendar days between two dates, with an option to include both endpoints. Leap years are handled automatically.
  2. Choose the mode or options, then run the tool.
  3. Review the result, then copy or download the TXT file.

Example

2026-01-01 → 2026-01-31 = 30 d

Details and limitations

Uses Gregorian calendar dates at UTC midnight, avoiding daylight-saving changes. Inclusive mode requires the end date to be on or after the start.

Text stays in your browser; it is not sent to a conversion server.

FAQ

Date Difference Calculator — What are the supported inputs and limits?

Uses Gregorian calendar dates at UTC midnight, avoiding daylight-saving changes. Inclusive mode requires the end date to be on or after the start.

Format references

Tool page updated: