Date Difference Calculator
Enter start and end dates (year/month/day) to get the days between, with cross-year support.
Input Data
Results
At a glance:The day difference is computed as (end date − start date) in days, handling cross-month and cross-year automatically (including leap years). Formula: day difference = ms difference (end − start) ÷ ms per day; weeks = day difference ÷ 7.
Formula
day difference = end date − start date (in days).
weeks = day difference ÷ 7.
Integer day difference, ignoring the time-of-day part.
How to Use
- Enter the start year, month, day.
- Enter the end year, month, day.
- The tool returns the days between and approximate weeks.
Case Studies
2026-01-01 to 2026-08-22
Jan 30 days (excl. 1/1), Feb 28, Mar 31, Apr 30, May 31, Jun 30, Jul 31, Aug 22 = 233 days total.
≈ 33.3 weeks.
FAQ
Does the difference include the start day itself?
This calculator computes the integer day difference between dates, i.e. end minus start. For example 1/1 to 1/2 is 1 day. If you want 'inclusive total days' (e.g. nights + 1), add 1 yourself.
Does a leap year affect it?
It is handled correctly. Feb 29 exists only in leap years; the system uses the real calendar, so periods crossing Feb 29 count one extra day.
Do I get a negative number if end is before start?
This tool returns the absolute value as a non-negative 'days between'. If you need a signed result (e.g. negative remaining days = expired), subtract start from end and judge the sign yourself.
How is it different from the age calculator?
The age calculator specifically computes age-to-today and days lived; this tool computes the gap between any two specified dates, more general for contracts and durations.
Does the time (hour) affect the result?
No. This calculator compares dates only (ignoring hours/minutes/seconds), using midnight as the base. For hour precision use a tool that includes time.
Why is weeks a decimal?
Weeks = days ÷ 7, so it is naturally fractional when not divisible (e.g. 10 days ≈ 1.43 weeks). Shown to one decimal for quick estimation.
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.