Tooloo

TOOLOO · DATE & TIME

Dates and time, with the assumptions spelled out

Count days, plan dates, or compare time zones. Start with what you need to do.

How many days between?

Calendar days; reversing the dates gives the same difference.

Dates are calculated in your browser

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Choose two dates to see the difference.

See weeks, months and weekday breakdown

INDEX / 03 GROUPS

All tools

Date calculations

Age CalculatorEnter a birth date to get an exact age, total days, and a countdown to the next birthday.Date Difference CalculatorFind the days, weeks, and months between two dates, split into weekdays and weekend days.Date Add and Subtract CalculatorMove a date forward or back by days, weeks, months, or years.Business Days CalculatorCount working days between two dates with your own weekend and holiday rules.

Calendar lookups

Day of the Week CalculatorFind what weekday any date falls on, with the surrounding month laid out.Days in Month CalculatorCheck how many days a given month has, with the whole year and leap-year status.ISO Week Number CalculatorFind the ISO week for a date, or the dates covered by a given week.

Time and time zones

Time Duration CalculatorWork out the hours between two times, including overnight shifts and unpaid breaks.Time Zone ConverterConvert one moment across several time zones with daylight saving applied automatically.Countdown TimerCount down to a target time and stay accurate through background tabs and sleep.

Why the assumptions are always visible

Age, date differences, working days, time zones, and countdowns — all calculated in your browser. Every tool states the rule it uses, because date answers usually differ over definitions rather than arithmetic.

Date disagreements are rarely arithmetic errors; they are definition mismatches. Including the end date changes the answer by one. Exact age and traditional age reckoning differ by a year or two. Adding a month to 31 January can land in February or March. A cross-border meeting is thrown off by daylight saving, not by the base offset. So every tool here shows the rule it applies and lets you change it rather than guessing for you.

Related tools

Unix Timestamp Converter ↗Cron Generator / Parser ↗