Date & Time Tools
Age, date arithmetic, days between dates, business days and countdowns.
Date and time tools that turn dates into decisions. Calculate exact age to the day, add or subtract days, months and years from any date, count the days between two dates, skip weekends and holidays with business-day math, and set up countdowns that stay accurate.
All tools
Age Calculator
Calculate exact age in years, months and days from any birth date.
Days Between Dates
Count the exact days, weeks, months and years between two dates.
Add or Subtract Days
Add or subtract days, weeks, months and years from any date.
Business Days Calculator
Count working days between two dates, excluding weekends and holidays.
Countdown to a Date
Days, weeks, months and years until — or since — any date.
5 tools · updated continuously
How these tools work
Date and time tools that turn dates into decisions. Calculate exact age to the day, add or subtract days, months and years from any date, count the days between two dates, skip weekends and holidays with business-day math, and set up countdowns that stay accurate. Every tool in this category publishes its formula, worked example and assumptions so you can verify the result yourself.
Frequently asked questions
How is age calculated exactly?
Age counts full years since the birth date, then full months within the current year, then remaining days. Leap years are handled correctly, including February 29 birthdays.
Do the day counters include both start and end dates?
Days between two dates counts the number of midnights from the start date to the end date, so the two dates are one day apart. Business days subtract weekends (and, when enabled, holidays).
How are February 29 birthdays handled in non-leap years?
In a non-leap year, a February 29 birthday is treated as February 28 for age purposes — a common legal convention — and the tool notes this on the results.