Date Calculator

Help & limits

Calendar days only, independent of time zones and DST. Same day = 0 (inclusive = 1). Reverse differences are negative. Year/month changes are combined, clamped to month end, then days are added. Supported years 0001–9999.

Example: 2024-02-28 + 1 day = 2024-02-29; Jan 31 + 1 month = month end

Runs in your browser. No upload.