Times & Dates is a free collection of time, date, and astronomy tools. Every tool runs in your browser with no sign-up, no ads inside the tool interface, and no download required. The site covers four areas: time zone conversion, date arithmetic, astronomy calculations, and calendar utilities.
A project manager in Berlin scheduling a standup with developers in Bangalore and San Francisco uses the Best Meeting Time Calculator to find hours that fall within working hours for all three cities. A traveler flying from Tokyo to London uses the Time Zone Converter to figure out what 2 PM JST means in GMT. A payroll team calculating overtime uses the Business Days Calculator to count working hours between shifts, excluding weekends and public holidays.
Astronomy hobbyists use the Sunrise and Sunset Calculator to plan photography sessions around golden hour. Developers working with APIs use the Unix Timestamp Converter to debug epoch values in log files. Event planners use the Countdown Timer to embed a live countdown on a landing page for a product launch.
Every time zone calculation on this site uses the IANA Time Zone Database, which is the same source used by Linux, macOS, Java, Python, and most programming languages. When a government changes daylight saving time rules, IANA publishes an update and the tools on this site pick it up. Astronomy calculations use the SunCalc library and Jean Meeus's Astronomical Algorithms for sun position, moon phases, and eclipse timing. Holiday data comes from the Nager.Date API, which covers over 100 countries.
All calculations happen in your browser. There is no server roundtrip for conversions, which means results appear instantly and your input data never leaves your device. The world clock page updates every second using your system clock synchronized with your operating system's time settings.
Daylight saving time changes the offset between cities twice a year, and the US and Europe switch on different dates. A meeting that works at 3 PM in March might not work at 3 PM in April because the offset between New York and London shifts from 5 hours to 4 hours. The tools on this site account for DST automatically when you pick a specific date. If you convert "3 PM New York to London" for a date in March, you get 7 PM. For the same conversion in April, you get 8 PM.
Leap seconds are another edge case. The last leap second was added on December 31, 2016, creating a 61-second minute. The Unix Timestamp Converter handles this by showing the raw epoch value, which does not include leap seconds, matching how most operating systems handle them.
The site includes over 30 tools. Time zone tools include the World Clock, Time Zone Converter, Time Zone Difference Calculator, and Time Zone Map. Date tools include the Date Calculator, Business Days Calculator, Age Calculator, Week Number Finder, and Countdown Timer. Astronomy tools cover Sunrise and Sunset, Moon Phase, Eclipse Calculator, and Sun Position. Calendar utilities include Holiday Lookup, Calendar Generator, and Military Time Converter.
Time zone data is updated when IANA releases new versions. Astronomy data is calculated from established algorithms and is accurate to within a few minutes for sun and moon events. Holiday data is sourced from Nager.Date and may not reflect last-minute government declarations.