Free Date & Time Tools
Free date and time calculators for the questions calendars make awkward to answer by hand. Work out your exact age in years, months, and days; measure the difference between two dates; count down the days until a deadline, holiday, or event; and convert Unix timestamps to and from readable dates. Each tool handles the fiddly parts correctly — leap years, varying month lengths, and time zones — and explains the counting method it uses (for example, whether the end date is included). Everything runs instantly in your browser with no sign-up. These are precise calendar calculations for planning and reference, not legal or official determinations of age or deadlines.
Which tool should you use?
- Date Difference Calculator
- Count the days, weeks, or months between two dates.
- Age Calculator
- Work out an exact age in years, months, and days from a birth date.
- Time Zone Converter
- Convert a time between cities and time zones.
- Countdown Timer
- Run a live countdown to a deadline or break.
- Business Days Calculator
- Add or count working days, skipping weekends.
- Unix Timestamp Converter
- Convert between a Unix timestamp and a human date.
Use this free Add or Subtract Days Calculator to find the exact date that falls a specified number of days before or after any starting date, accounting for month lengths and leap years automatically.
Find your exact age in years, months, and days from a date of birth, plus your total age in days and a countdown to your next birthday.
Count the working days between two dates, or add and subtract business days from a start date — weekends are excluded automatically.
Set a duration in hours, minutes, and seconds, then start a live countdown that beeps when it reaches zero. Pause, resume, and reset anytime — all in your browser.
Pick a future date and time and watch a live countdown of the days, hours, minutes, and seconds remaining, updating every second.
Enter any target date to instantly see how many days, weeks, and months remain until that date, or how many days have elapsed since a date in the past.
Find the time between any two dates — in years, months, and days, and as a total number of days and weeks.
Instantly find the day of the week for any date in history or the future — simply enter a date and get the result in seconds.
Count how many days are left until a future date, such as a holiday, deadline, birthday, or event.
Start, stop, and reset a precise stopwatch and record lap times to the centisecond. It runs entirely in your browser with no install or sign-up.
Calculate the exact time duration between any two points in time — whether measuring hours between clock times or the full span of days, hours, and minutes between two dates.
Convert a specific date and time from one time zone to another, with daylight saving time handled automatically by your browser's built-in time-zone data.
Find the ISO 8601 week number for any date, or look up the Monday-to-Sunday date range for a given week number and year.
Calculate exactly how many hours and minutes you worked between a start time and an end time, with optional break deduction and a weekly total across up to 7 days.
Look up the current local time in any of 40+ major cities worldwide, compare multiple time zones side-by-side, and see each city's location on an interactive map.
Frequently asked questions
How is age calculated?
As completed years, months, and days from the start date to today (or any target date), accounting for different month lengths and leap years.
Do these count calendar days or business days?
The date difference tool counts calendar days and shows the exact number of days between two dates.
Do the date tools handle leap years?
Yes. All date calculations account for leap years automatically.