Free time and date tools — a live world clock for every US time zone and world city, a date calculator for days between dates, a time calculator to add and subtract time, an hours calculator for work hours, and a weekly time card calculator with breaks, overtime and pay. Fast, accurate, and completely free — no sign-up.
Whether you need to know what time it is in another country, how many days are between two dates, or how many hours you worked this week, these six tools cover the everyday time-and-date questions people search for most. They run instantly in your browser, are accurate to the second and the day, and automatically handle Daylight Saving Time and time-zone offsets worldwide.
See the current time in all US time zones — Eastern, Central, Mountain, Pacific, Alaska and Hawaii — plus London, Tokyo, Dubai, Sydney and any city on Earth. Open the world clock →
Count the days, weeks, months or business days between two dates, or add and subtract days to find a future or past date. Open the date calculator →
Add and subtract time, find the hours between two times, and convert between hours, minutes and seconds. Open the time calculator →
Build a weekly work-hours time card with breaks, overtime and gross pay, using federal FLSA overtime rules. Open the hours calculator →
Need to convert a specific time between two zones? Try the Time Zone Converter. Counting down to an event? Use the Countdown Timer, or work out an exact age in years, months and days.
Adding a month to a date has no single correct answer, which is why date tools disagree with each other and with spreadsheets. Months are not a fixed length, so a month after 31 January can reasonably be the last day of February or an overflow into March, and different systems choose differently. Adding days is unambiguous; adding months and years is a convention, and any tool that handles them is applying a rule rather than computing a value.
Leap years follow a rule with two exceptions that most people only half remember: a year divisible by four is a leap year, unless it is divisible by 100, unless it is also divisible by 400. That is why 2000 was a leap year and 2100 will not be — a distinction that has already caused real failures in software written by people who tested only the first part of the rule. Over any span crossing a century boundary, an age or duration calculated without it is a day out.
Days are not all the same length either. Where daylight saving applies, one day each year has 23 hours and another has 25, so a duration in days and the same duration in hours can genuinely disagree. Time zones compound this: offsets are not all whole hours — India runs at half past, Nepal at three quarters — and a few regions shift their rules from year to year. Anything scheduled across zones is safest stored as an absolute instant and converted for display, rather than stored as a local wall-clock time.
Business-day calculations add a layer that is not astronomical at all but legal. Weekends are consistent, holidays are not: they vary by country, by state and sometimes by industry, and several move each year. A tool that counts working days is applying a specific holiday list, so a result is only as correct as that list is for your jurisdiction — which is why a contractual deadline should always be checked against the calendar that governs the contract.