Time & everyday tools
Four tools for time and small everyday decisions: converting a Unix timestamp, working out what time a meeting is somewhere else, keeping a focus timer running, and picking a name fairly.
They use what your browser already knows — its clock, its time-zone database and its secure random number generator — so there is nothing to download and nothing sent anywhere.
All tools 4
Which tool for which job
- Read a Unix timestamp from a log or an APIThe Timestamp Converter detects seconds or milliseconds and shows the moment in UTC, in your local time, as ISO 8601 and as a relative time such as “3 days ago”. It converts dates back to timestamps too.
- Work out what 3 PM Pacific is in LondonThe Time Zone Converter converts a date and time between zones and applies daylight saving for the specific date you chose.
- Work in focused sprintsThe Pomodoro Timer alternates focus and break periods — 25 and 5 minutes by default — with a beep at each change and the countdown shown in the browser tab.
- Pick a winner, or put a list in random orderThe Random Picker draws one entry or shuffles the whole list, using your browser's cryptographic random source so that every entry has exactly the same chance.
Limits worth knowing
- Ten digits means seconds, thirteen means milliseconds. The timestamp converter uses that rule to guess, and lets you set the unit yourself for unusual data. It accepts whole numbers only.
- A timestamp has no time zone. It counts seconds since midnight UTC on 1 January 1970; only the readable form changes with your zone.
- The time zone list covers UTC, your own zone and 17 major zones. There is no city search — pick a city that shares your zone.
- The US and Europe change their clocks on different weekends. For a few weeks each spring and autumn the usual gap between them is an hour out, which is why you should always convert with the real date.
- Browsers slow down timers in hidden tabs, so a Pomodoro countdown can fall behind if the page sits in the background for a long time. Keep the tab visible, and keep the sound on: the alert is a beep, not a system notification.
- The Pomodoro timer alternates two periods. The longer break after every fourth session is left to you.
- The random picker keeps no record. For a public giveaway, record your screen as proof. An entry listed twice has two chances, which is a simple way to weight a draw.
How these tools work
The timestamp and time zone converters use JavaScript's Date object and the Intl time-zone database built into your browser — the same rules your operating system uses. The Pomodoro timer's beep is generated with the Web Audio API, so there is no sound file to load. The random picker draws from crypto.getRandomValues and shuffles with the Fisher–Yates algorithm, which makes every ordering equally likely.
Guides: Unix timestamps and time zones, demystified · Why Toolkit runs entirely in your browser (and why that matters)
More on Toolkit: Image, media & file tools · Text & writing tools · Developer & data tools · Security & privacy tools · Network & web tools · Calculators · Games
Frequently asked questions
Is the random picker really fair?
Yes. It uses the browser's cryptographically secure random generator rather than the ordinary one, and it corrects for the small bias that naive methods introduce, so every entry has exactly the same chance. Shuffles use the Fisher–Yates algorithm, which makes every possible order equally likely.
Does the time zone converter handle daylight saving time?
Yes. It looks up the offset that is actually in force in each zone on the date you enter, so a conversion in July and one in January can give different answers for the same two cities.
Is a Unix timestamp in seconds or milliseconds?
Both are in use. Traditional Unix time counts seconds and is currently ten digits long; JavaScript and many APIs count milliseconds, which gives thirteen digits. The converter tells them apart by length and lets you override its guess.
Will the Pomodoro timer keep running in a background tab?
It keeps counting, but browsers deliberately slow down timers in tabs you are not looking at, so it can fall behind over a long stretch. Keeping the tab visible, or in its own small window, is the most reliable setup.