Date and Time Calculators
Work out ages, durations, deadlines, and other date and time questions.
Number of Calculators: 11
What to Know
Every calculator here answers a version of "how much time is that, really" — from Age and Days Between Dates to more specific questions like Business Days (skips weekends and holidays) or Time Zone (handles Daylight Saving Time correctly using the real IANA time zone database, not a hand-maintained rule list).
Sleep Cycle and Day of the Week round out the set with quick, single-purpose lookups. If you're tracking hours for payroll rather than a personal date question, Hours and Time Card are built specifically for that, including overnight shifts that cross midnight.
- AgeFind your exact age in years, months, and days (or weeks), as of today or any date, plus a countdown to your next birthday.
- Date & Time DurationFind the exact duration between two dates and times — in days, hours, and minutes, or weeks and remaining days.
- Days Until / CountdownFind out exactly how many days, weeks, and days remain until a date — or how long ago it was.
- Hours WorkedCalculate total hours worked between a clock-in and clock-out time, minus any unpaid break, plus total pay at an hourly rate.
- Time DurationAdd or subtract two time durations in hours, minutes, and seconds.
- Time CardAdd up a full work week of daily clock-in and clock-out times into total hours, with regular vs. overtime pay.
- Day of the WeekFind out what day of the week any past, present, or future date falls on.
- Week NumberFind the ISO 8601 week number for any date, or find the calendar dates a given ISO week covers.
- Sleep CycleFind the best bedtime or wake-up time based on 90-minute sleep cycles, so you wake up between cycles instead of in the middle of one.
- Time ZoneConvert a date and time from one time zone to another, including Daylight Saving Time.
- Business DaysCount the number of business days (weekdays) between two dates, or find the date a number of business days from now.