WatchTimeYour local time
The time tools you need for your daily workflow
Twelve tools, one job each
Free utilities for everyday time questions — what time it is somewhere else, how many days until a deadline, exactly how old someone is, or what a Unix timestamp means.
Local Zone Time
Live current time in major cities across every continent, with dates and UTC offsets.
The time tools you needTime Zone Converter
Convert any time between two zones — daylight saving is handled automatically.
The time tools you needDate Calculator
Days, weeks, months, and years between any two dates, plus add-or-subtract days.
The time tools you needAge Calculator
Exact age in years, months, and days — and how long until the next birthday.
The time tools you needCountdown Timer
Count down to any date and time, and share the countdown with a link.
The time tools you needUnix Timestamp
Turn epoch seconds into a readable date and back — with the current timestamp live.
The time tools you needWeek Number
Today's ISO 8601 week number, how it's calculated, and a full-year week table.
The time tools you needStopwatch
A big, precise stopwatch with lap times that stays correct even in a background tab.
The time tools you needBorn on What Day
The day of the week for any date of birth — and your birthday's weekday this year.
The time tools you needAge Difference
The exact age gap in years, months, and days between two people or two dates.
The time tools you needDays Until Christmas
How many days remain until the next 25 December, with the exact date displayed.
The time tools you needMeeting Planner
Add up to five cities and find the hours that overlap for everyone.
The time tools you needWhy another time site?
Most time websites bury a thirty-second answer under pop-ups, autoplaying video, and pages of boilerplate. WatchTime Online takes the opposite approach. Each tool lives on its own fast, single-purpose page. The calculation runs in your browser, nothing you type is sent to a server, and the explanation under each tool tells you how the math actually works — so you can sanity-check the result instead of taking it on faith.
That last part matters more than it sounds. Date arithmetic is full of traps: months have four different lengths, leap years skip most century years but not all of them, and daylight saving time means one day a year has 23 hours and another has 25. A calculator that hides its method can quietly get these wrong. Every page here documents the rules it follows — ISO 8601 week numbering, calendar-month age counting, IANA time zone data — so the results are reproducible anywhere.
Common questions
Is the clock on this page accurate?
The clock reads your own device's system time, which on any modern phone or computer is synchronized over the internet (via NTP) and is typically accurate to well under a second. If the clock looks wrong, your device's time zone or clock settings are the place to fix it.
Do the tools store what I enter?
No. Every calculator runs entirely in your browser using JavaScript. Dates, birthdays, and timestamps you type are never transmitted or stored. See the privacy policy for details on the analytics and advertising cookies the site itself uses.
Which time zone database do the tools use?
The world clock and zone converter rely on your browser's built-in implementation of the IANA time zone database — the same reference data used by operating systems worldwide. That means daylight saving rules and historical offset changes are handled by data that your browser vendor keeps up to date.
Can I use these tools on my phone?
Yes. Every page is a lightweight, responsive page with no app to install. Bookmark the tool you use most; it will load in under a second on a typical connection.