--- title: "All Time & Date Tools — Clocks, Converters and Calculators | WatchTime Online" url: https://watchtimeonline.com/tools/index.html description: "Every free tool on WatchTime Online in one place: world clock, time zone converter, meeting planner, date and age calculators, timers, plus 29 city time pages." --- [Home](https://watchtimeonline.com/) › All Tools # All time and date tools 25 free calculators and clocks, plus 29 city time pages and 22 time-difference comparisons — grouped by the question they answer. ## Clocks and time zones For anything that crosses a border: what time it is somewhere else, when a call works for everyone, and when a plane actually lands. Every one of these uses the IANA time zone database, so daylight saving changes are applied for the exact date you enter, not today's offset. - [Local Zone Time & World Clock](https://watchtimeonline.com/tools/world-clock.html) — Your exact local time, 28 live city clocks and a 110-city directory with UTC offsets and weather. - [Time Zone Converter](https://watchtimeonline.com/tools/time-zone-converter.html) — Convert a date and time between any two zones, including the date change when you cross midnight. - [Meeting Planner](https://watchtimeonline.com/tools/meeting-planner.html) — Line up working hours in up to five cities and see the overlap highlighted. - [Flight Arrival Calculator](https://watchtimeonline.com/tools/flight-arrival-calculator.html) — Departure time plus flight length gives your local landing time — date line and DST included. - [Unix Timestamp Converter](https://watchtimeonline.com/tools/unix-timestamp-converter.html) — Turn epoch seconds or milliseconds into a readable date, or a date into a timestamp. - [Embeddable Clock Widget](https://watchtimeonline.com/tools/embed-widget.html) — Generate a live clock for any city and paste it into your own website. ## Date and calendar calculators Date math is where most mistakes happen — month lengths, leap years, whether the end date counts. These calculators show their working and say which convention they use, so you can check a result instead of just trusting it. - [Date Calculator](https://watchtimeonline.com/tools/date-calculator.html) — Days between two dates, or add and subtract days from any date. Shareable result links. - [Business Days Calculator](https://watchtimeonline.com/tools/business-days-calculator.html) — Count working days between dates or add them to a deadline, with custom weekends and U.S. holidays. - [Age Calculator](https://watchtimeonline.com/tools/age-calculator.html) — Exact age in years, months and days, plus total days lived and the next birthday. - [Age Difference Calculator](https://watchtimeonline.com/tools/age-difference-calculator.html) — The exact gap between two birthdays or any two dates. - [Born on What Day](https://watchtimeonline.com/tools/born-on-what-day.html) — Find the weekday for any birth date, and which weekday your birthday falls on this year. - [ISO Week Number](https://watchtimeonline.com/tools/week-number.html) — Today's ISO 8601 week with its Monday–Sunday range, plus a lookup for any date. - [Calendar & Reminders](https://watchtimeonline.com/tools/calendar.html) — A simple calendar with recurring events and email or browser reminders. ## Timers and countdowns Live timers that keep accurate time even when you switch tabs. - [Countdown Timer](https://watchtimeonline.com/tools/countdown-timer.html) — Count down to any date and time, and share the countdown with a link. - [Days Until Christmas](https://watchtimeonline.com/tools/days-until-christmas.html) — A live countdown to 25 December, plus Thanksgiving, Black Friday and Christmas Eve. - [Online Stopwatch](https://watchtimeonline.com/tools/stopwatch.html) — A large, accurate stopwatch with lap times that survives tab switches. ## Planning your day Tools for the time you actually have: sleep, commitments and routines. Everything you enter stays in your browser. - [Bedtime Calculator](https://watchtimeonline.com/tools/bedtime-calculator.html) — Bed and wake-up times based on 90-minute sleep cycles. - [Busy Score](https://watchtimeonline.com/tools/busy-score.html) — Add up today's meetings and commitments to get a 0–100 read on how full your day is. - [Daily Time Audit](https://watchtimeonline.com/tools/daily-time-audit.html) — Split your 24 hours into categories and see how much time is genuinely unclaimed. - [Routine Builder](https://watchtimeonline.com/tools/routine-builder.html) — Build a routine block by block on a 24-hour timeline and spot gaps and overlaps. - [Habit Clock](https://watchtimeonline.com/tools/habit-clock.html) — Short timed habit sessions with a daily streak. ## Daily extras Small things that change every day. - [Daily Briefing](https://watchtimeonline.com/tools/daily-briefing.html) — Today's hottest and coldest cities, longest and shortest days, moon phase and upcoming clock changes. - [Time Zone Fact of the Day](https://watchtimeonline.com/tools/daily-fact.html) — A new fact about odd offsets, date-line jumps and how standard time came about. - [Daily Time Puzzle](https://watchtimeonline.com/tools/time-puzzle.html) — Guess the local time in a mystery city and build a streak. - [Local Weather](https://watchtimeonline.com/tools/weather.html) — Current conditions, hourly outlook and 7-day forecast for any city. ## Current time by city Each city page has a live clock, the city's daylight saving dates, sunrise and sunset, the best hours to call from other regions, and a short history of how the city came to keep the time it does. - [Auckland](https://watchtimeonline.com/tools/city/auckland.html) - [Bangkok](https://watchtimeonline.com/tools/city/bangkok.html) - [Berlin](https://watchtimeonline.com/tools/city/berlin.html) - [Boston](https://watchtimeonline.com/tools/city/boston.html) - [Buenos Aires](https://watchtimeonline.com/tools/city/buenos-aires.html) - [Cairo](https://watchtimeonline.com/tools/city/cairo.html) - [Chicago](https://watchtimeonline.com/tools/city/chicago.html) - [Denver](https://watchtimeonline.com/tools/city/denver.html) - [Dubai](https://watchtimeonline.com/tools/city/dubai.html) - [Hong Kong](https://watchtimeonline.com/tools/city/hong-kong.html) - [Istanbul](https://watchtimeonline.com/tools/city/istanbul.html) - [Johannesburg](https://watchtimeonline.com/tools/city/johannesburg.html) - [London](https://watchtimeonline.com/tools/city/london.html) - [Los Angeles](https://watchtimeonline.com/tools/city/los-angeles.html) - [Madrid](https://watchtimeonline.com/tools/city/madrid.html) - [Mexico City](https://watchtimeonline.com/tools/city/mexico-city.html) - [Milan](https://watchtimeonline.com/tools/city/milan.html) - [Moscow](https://watchtimeonline.com/tools/city/moscow.html) - [Mumbai](https://watchtimeonline.com/tools/city/mumbai.html) - [New York](https://watchtimeonline.com/tools/city/new-york.html) - [Paris](https://watchtimeonline.com/tools/city/paris.html) - [Santo Domingo](https://watchtimeonline.com/tools/city/santo-domingo.html) - [São Paulo](https://watchtimeonline.com/tools/city/sao-paulo.html) - [Seoul](https://watchtimeonline.com/tools/city/seoul.html) - [Shanghai](https://watchtimeonline.com/tools/city/shanghai.html) - [Singapore](https://watchtimeonline.com/tools/city/singapore.html) - [Sydney](https://watchtimeonline.com/tools/city/sydney.html) - [Tokyo](https://watchtimeonline.com/tools/city/tokyo.html) - [Toronto](https://watchtimeonline.com/tools/city/toronto.html) ## Time differences between cities Side-by-side comparisons for city pairs that people schedule between most often, including how the gap changes when only one side observes daylight saving. - [Bangkok vs Sydney Time Difference](https://watchtimeonline.com/tools/compare/bangkok-vs-sydney.html) - [Buenos Aires vs New York Time Difference](https://watchtimeonline.com/tools/compare/buenos-aires-vs-new-york.html) - [Cairo vs London Time Difference](https://watchtimeonline.com/tools/compare/cairo-vs-london.html) - [Chicago vs Tokyo Time Difference](https://watchtimeonline.com/tools/compare/chicago-vs-tokyo.html) - [Dubai vs Istanbul Time Difference](https://watchtimeonline.com/tools/compare/dubai-vs-istanbul.html) - [Dubai vs Mumbai Time Difference](https://watchtimeonline.com/tools/compare/dubai-vs-mumbai.html) - [Hong Kong vs Singapore Time Difference](https://watchtimeonline.com/tools/compare/hong-kong-vs-singapore.html) - [London vs Dubai Time Difference](https://watchtimeonline.com/tools/compare/london-vs-dubai.html) - [Los Angeles vs Tokyo Time Difference](https://watchtimeonline.com/tools/compare/los-angeles-vs-tokyo.html) - [Mexico City vs New York Time Difference](https://watchtimeonline.com/tools/compare/mexico-city-vs-new-york.html) - [Milan vs New York Time Difference](https://watchtimeonline.com/tools/compare/milan-vs-new-york.html) - [Mumbai vs New York Time Difference](https://watchtimeonline.com/tools/compare/mumbai-vs-new-york.html) - [New York vs London Time Difference](https://watchtimeonline.com/tools/compare/new-york-vs-london.html) - [New York vs Los Angeles Time Difference](https://watchtimeonline.com/tools/compare/new-york-vs-los-angeles.html) - [New York vs Toronto Time Difference](https://watchtimeonline.com/tools/compare/new-york-vs-toronto.html) - [Paris vs New York Time Difference](https://watchtimeonline.com/tools/compare/paris-vs-new-york.html) - [Santo Domingo vs New York Time Difference](https://watchtimeonline.com/tools/compare/santo-domingo-vs-new-york.html) - [Shanghai vs London Time Difference](https://watchtimeonline.com/tools/compare/shanghai-vs-london.html) - [Singapore vs London Time Difference](https://watchtimeonline.com/tools/compare/singapore-vs-london.html) - [Sydney vs London Time Difference](https://watchtimeonline.com/tools/compare/sydney-vs-london.html) - [Tokyo vs Seoul Time Difference](https://watchtimeonline.com/tools/compare/tokyo-vs-seoul.html) - [Toronto vs London Time Difference](https://watchtimeonline.com/tools/compare/toronto-vs-london.html) ## How these tools work Every clock and converter on WatchTime Online runs in your browser. Times come from your device clock, and time zone rules come from the IANA time zone database built into modern browsers — the same database used by operating systems and airline booking systems. That's why the converter knows that London moves to summer time on a different weekend than New York, and why a calculation for a date next March uses next March's offset rather than today's. Nothing you type into a calculator is sent to a server. The two exceptions are the weather pages, which ask Open-Meteo for a forecast, and the calendar, which stores events so it can send reminders. Both are explained in the [privacy policy](https://watchtimeonline.com/privacy-policy.html). If you'd like the reasoning behind the numbers — why some years have 53 ISO weeks, or why there are more than 24 time zones — the [guides](https://watchtimeonline.com/guides/index.html) cover the rules in plain English. Found a result that looks wrong? [Tell me](https://watchtimeonline.com/contact.html) and I'll check it. --- Source: https://watchtimeonline.com/tools/index.html