Date and time calculators for deadlines, events and time zones
Four calculators for the date questions that come up in planning: how many days apart two dates are, how long until an event, how long you have been together, and what time it is somewhere else.
When would you use these?
Dates are easy until you need an exact answer. How many days until the lease ends? What is the date 90 days from today? Is the deadline really ten business days away? The date calculator handles all three: the days between two dates, adding or subtracting days, weeks, months or years, and business days that skip weekends and U.S. federal holidays.
When you are waiting for a particular day, the countdown calculator shows how many days are left, with milestone markers, saved countdown cards you can come back to, and a shareable image. It also counts up from a past date, which is handy for streaks. For couples and milestones, the anniversary calculator counts the days you have been together and lists the upcoming 100-day, 1,000-day and yearly milestones.
For people and meetings in different places, the time zone converter converts a time between cities around the world, shows when the date changes, explains daylight saving time, and highlights meeting times that fall in work hours in both places. If your question is about working days or prorated pay, the working days calculator in School & Work goes further.
Which tool does what
| Tool | Answers | Useful if you are |
|---|---|---|
| Date Calculator | Days between dates, a date N days or months away, and business days | Deadlines, notice periods, lease and contract dates |
| Countdown Calculator | Days left until (or since) a date, with milestones and saved cards | Trips, holidays, weddings, streaks |
| Anniversary Calculator | Days together and the next 100-day, 1,000-day and yearly milestones | Dating and wedding anniversaries, business or adoption dates |
| Time Zone Converter | Time in another city, the day change, and daylight saving notes | Scheduling calls and travel across regions |
Frequently asked questions
Does the date calculator include the start date?
By default it does not, so January 1 to January 2 is one day. Tick the include-start option if both the first and last day should count.
Which holidays are skipped when counting business days?
The U.S. federal holidays, using the observed date when a holiday falls on a weekend. Your employer, bank or court may use a different list.
How does the time zone converter handle daylight saving time?
It reads the rules from your browser's time zone database for the exact date you enter, so the difference between cities is correct even in the weeks when regions change clocks on different days.
Why does my countdown show a different number tomorrow?
Countdowns compare with today's date on your device, so the number changes at your local midnight. Saved cards recount whenever you open the page.
Are my dates saved?
Dates are processed in your browser. Saved countdown cards stay only in your own browser and are never sent to a server.
Results are for planning. For legal, tax or contract deadlines, confirm the exact rules that apply to you.