Date Calculator
Fast, free, and private. Every calculation runs in your browser and no data ever leaves this page.
Days between two dates
Days0
In weeks0
Weekdays
Add or subtract time
Month and year math clamps to the end of the month: Jan 31 plus one month is Feb 28 (Feb 29 in a leap year).
Result
Day of week
Business days
Counts weekdays strictly after the start date through the end date. Holiday list uses federal observed dates for 2026 and 2027.
Business days0
Age in days, weeks, and months
Age
Total days0
Total weeks0
Total months0
How date math works here
- Pick a tab: days between dates, add or subtract time, business days, or age.
- Results update instantly as you type, with no page reload.
- All math uses UTC dates, so daylight saving time and time zones never skew a result.
Common uses
- Count days until a deadline, contract date, or event.
- Find the date 90 days from today for payment terms and planning.
- Count business days for project schedules, minus weekends and federal holidays.
- Check exact age in years, months, and days for forms and eligibility.
This tool provides date calculations for planning purposes. Verify critical dates independently.