Date Calculator
Time
Two modes in one tool. 'Add / Subtract' lets you start from a date and offset it by any combination of years, months, weeks, plain days, or business-only days — useful for figuring out a deadline, a contract end, or 100 days from today. 'Between' takes a start and end date and returns the exact difference (years / months / days), plus totals in days, weeks, months, and business days.
Result
Thu, Jul 2, 2026
2026-07-02
How to use
- Pick a mode: Add / Subtract or Between.
- Set the date(s) and any offsets you want.
- Read the resulting date or the breakdown between the two dates.
Frequently asked questions
- What counts as a business day?
- Monday through Friday. Public holidays aren't subtracted — they vary by country. For an exact deadline in your jurisdiction, double-check against the local holiday calendar.
- How are months handled?
- By calendar month. Adding 1 month to Jan 31 gives Mar 3 (because Feb has 28 days that year), then the day overflow rolls into the next month. This matches how most spreadsheets and SQL databases do month arithmetic.
- Why does 'years 0 months 11 days 30' show instead of '1 year'?
- The Between view always uses calendar components — full calendar years first, then remaining months, then remaining days. 11 months + 30 days is not a full year because the next month might be 31 days.
- Is the date stored?
- Only in your browser's local storage so the inputs survive a reload. Nothing is uploaded.
Related tools
World Clock
See several time zones side by side with live updates and offset differences from your local time.
Time Difference Calculator
Calculate the exact difference between two date-times, broken down into days, hours, minutes, and seconds.
Timezone Converter
Convert a date and time between any two world timezones, including DST.
Unix Timestamp Converter
Convert Unix timestamps to dates and dates back to timestamps.
Stopwatch & Timer
A precise stopwatch with laps and a countdown timer with an alarm.
D-Day Calculator
Count the days between two dates, or the countdown to a target date.