Time & Date Calculators
Dates and time are deceptively hard to compute by hand, because months vary in length, leap years add a day, and clock time counts in base 60. These calculators handle all of that so the answer is always exact.
Each tool answers a different question: a span between two calendar dates, an exact age broken down, a duration added or subtracted, or hours worked with breaks. Choosing the right one below avoids the classic off-by-one mistakes.
The guides walk through the methods — counting days between dates, and calculating hours worked — if you want to reproduce the results yourself.
Which calculator should I use?
- Age Calculator Exact age in years, months and days from a birth date. Open calculator →
- Date Calculator Days between two dates, or add/subtract days from a date. Open calculator →
- Time Calculator Add or subtract durations in days, hours, minutes, seconds. Open calculator →
- Hours Calculator Hours worked between two clock times, minus breaks. Open calculator →
Guides on this topic
- Calculating Days Between Dates How to count the days between two dates and add or subtract days for deadlines and due dates — with the leap-year and month-length details handled for you.
- How to Calculate Your Exact Age Working out an exact age in years, months and days is trickier than it looks — here's why leap years and month lengths matter, and how to get it right every time.
- How to Calculate Hours Worked Turn clock-in and clock-out times into hours and decimal hours for payroll — including breaks and overnight shifts — without the arithmetic headaches.