Home/Date & Time

Date & Time Tools

Count days, convert timezones, plan and schedule.

Free date and time tools: date difference, days until, business days, timezone converter, week number, timesheet and countdown calculators. Instant, client-side, no sign-up. All 27 tools below are free, run entirely in your browser, and need no sign-up.

Date Difference Calculator

Find the exact difference between two dates in years, months and days, plus the total number of days, weeks, hours and minutes between them.

Days Until Date

Count how many days are left until any future date. A live countdown showing days, weeks, hours and minutes remaining until your target day.

Add Days to Date

Add a number of days, weeks, months or years to any date and get the exact resulting calendar date, including the day of the week.

Subtract Days from Date

Subtract days, weeks, months or years from any date to find a past calendar date, complete with the exact day of the week it falls on.

Business Days Calculator

Count the working days between two dates, excluding weekends. See business days, total days, weekend days and full weeks in the range.

Add Business Days to Date

Add a number of working days to a start date, skipping weekends, to find the resulting business date and the day of the week it lands on.

ISO Week Number Calculator

Find the ISO 8601 week number for any date, plus the week year, the day of the week and the range of dates that week covers.

Day of the Week Finder

Find out what day of the week any date falls on, past or future. Enter a birthday or historic date and see the exact weekday instantly.

Leap Year Checker

Check whether any year is a leap year and see why. Lists the next several leap years and shows how many days that year has.

Days in Month Calculator

See how many days are in any month of any year, including February in leap years, plus the first and last weekday of that month.

Time Duration Calculator

Add or subtract times in hours, minutes and seconds. Combine multiple durations and get the total in HH:MM:SS and in decimal hours.

World Time Zone Converter

Convert a time from one time zone to another using real IANA zones. Pick a date and time, choose two cities, and see the matching local time.

Hours Worked Calculator

Calculate total hours worked from a clock in and clock out time, minus break minutes. Shows hours and minutes plus decimal hours for pay.

Weekly Timesheet Calculator

Add up hours across a full week from daily clock in and clock out times with breaks. See each day and the weekly total in decimal hours.

Sleep Bedtime Calculator

Find the best times to go to sleep or wake up based on 90 minute sleep cycles, so you wake between cycles feeling more refreshed.

Countdown to Date and Time

A live countdown to any date and time. Watch the days, hours, minutes and seconds tick down to a launch, event or deadline in real time.

Time Lived Calculator

See how long you have been alive in total days, hours, minutes and seconds from your birth date, updated live down to the second.

Day of the Year Calculator

Find which numbered day of the year any date is, from 1 to 365 or 366, plus how many days are left in the year and the percentage elapsed.

Next Birthday Countdown

Count down to your next birthday. Enter your birth date to see the days until it, the weekday it falls on, and the age you will turn.

Weekday Occurrence Counter

Count how many times each weekday occurs between two dates. See exactly how many Mondays, Fridays or any weekday fall in your date range.

Duration Between Two Times

Work out how long is between two clock times on the same day or overnight. Get the gap in hours and minutes and in decimal hours.

Quarter of the Year Finder

Find which fiscal quarter a date falls in. See the quarter number, its start and end dates, and how many days are left in that quarter.

Moon Phase Calculator

Find the moon phase for any date. See the phase name, illumination percent and the moon age in days, computed from the lunar cycle.

Date to Ordinal and Long Format

Convert a date into ordinal and long written formats. See the 1st, 2nd, 3rd style day, the full spelled out date and other common formats.

Week of the Month Finder

Find which week of the month a date falls in and which occurrence of that weekday it is, like the second Tuesday or the last Friday.

Live Unix Time Clock

A live clock showing the current Unix epoch time in seconds and milliseconds, plus the matching UTC and local date and time, updating each second.

Time Ago Calculator

Turn a past date and time into a plain time ago phrase like 3 days ago or 5 months ago, plus the exact elapsed days, hours and minutes.

Frequently asked questions

Are these date & time tools free?

Yes. Every date & time tool on yourhack.ai is completely free, with no sign-up and no usage limits.

Do these date & time tools work on mobile?

Yes. They run in any modern web browser on phone, tablet or desktop. There is nothing to install.

Is my data private?

Yes. These tools run entirely in your browser, so nothing you enter is uploaded to a server.

How many date & time tools are there?

There are currently 27 free date & time tools here, and we add more regularly.

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