Date Difference Calculator

Count how much time is between two dates. Pick a start and end date and get the difference several ways.

What it shows

• Total days — the exact whole-day count between the two dates.
• Weeks — the same span in weeks.
• Years / months / days — a calendar breakdown that accounts for different month lengths and leap years.

The order doesn't matter — the tool always returns the absolute difference, so swapping start and end gives the same answer.

Common uses

• Days until a deadline or event (a D-day countdown).
• Time since an anniversary, launch, or birthday.
• Trip length, project duration, notice periods, and billing cycles.

Notes

• Counting uses UTC dates, so results aren't shifted by time zones or daylight saving.
• It runs entirely in your browser — nothing is uploaded, and it works offline.