About Lifespan Lab
Lifespan Lab has free calculators for dates and time. Find your exact age in years, months and days, count the days between two dates, add or subtract days from a date, see your whole life as a grid of weeks, plan bedtimes around sleep cycles, and count down to a birthday, a holiday or any event.
Which calculator do I need?
- Your age today, or someone's age on a past or future date: Age Calculator.
- Days between two dates, with business days and weeks: Date Calculator.
- A live countdown you can share by link: Countdown to Any Date.
- Your life in weeks, a simple way to see time already lived and still ahead: Your Life in Weeks.
- When to go to bed so you wake up between sleep cycles: Sleep calculator.
- Quick answers such as 30 days from today or 90 days from today.
Good to know
All dates use your device's own calendar and time zone. Leap years and month lengths are handled for you, so 31 January plus one month is the end of February. Nothing you enter leaves your browser.