Add your input
A start date and an end date.
Time keeper
Date difference calculator
Measure a date span with inclusive-day control.
Privacy built inYour work stays with you
End is after start
Calendar difference
0y 1m 0d
Total days
31 days
Total weeks
4.429 weeks
Total hours
744 hours
Your work stays private in your browser while you use this tool.
What does date difference calculator do?
The date difference calculator compares two ISO calendar dates and reports a calendar breakdown in years, months, and days plus absolute totals in days, weeks, and hours. It also states which date comes first.
- Input
- A start date and an end date.
- Result
- Elapsed days and a human-readable duration.
- Price
- Free
- Account
- Not required
How to use date difference calculator
Choose your settings
Measure a date span with inclusive-day control.
Save or copy
Elapsed days and a human-readable duration.
A practical tip
Decide whether both endpoints should count when comparing deadlines or stays.
When to use date difference calculator
Measure the elapsed days between a project kickoff and delivery date.
Compare a contract start and end date as both calendar months and total days.
Check the duration between two historical dates without local-time daylight-saving shifts.
Worked example
A concrete date difference calculator example
- Input
- Start: 2024-01-01; end: 2024-02-01
- Result
- 0 years, 1 month, 0 days; 31 total days; 4.429 weeks; 744 hours.
What to expect
How it works
Date-only values are validated as YYYY-MM-DD and represented at UTC midnight. The calendar result advances whole years and then whole months from the earlier date before counting remaining days; totals divide the millisecond interval by fixed UTC day, week, and hour lengths.
Know before using
Limits and edge cases
- Total days measure elapsed midnights and do not include both endpoints; there is no inclusive-day option in this calculator.
- Month-end rollover follows JavaScript calendar arithmetic, so spans involving dates such as the 29th–31st may differ from billing, legal, or financial day-count conventions.
Common questions
Date difference calculator FAQ
Is date difference calculator free to use?
Yes. Date difference calculator is free to use.
Does date difference calculator keep my work private?
Yes. Your work stays private while you use the tool — nothing you enter is uploaded.
What happens if the end date is before the start date?
The tool labels the direction, while the calendar breakdown and numeric totals are shown as positive magnitudes between the two dates.
Does January 1 to January 2 count as one or two days?
It counts as one elapsed day. For endpoint-inclusive weekday counting, use the business-days calculator and enable its endpoint option.