All tools › Clock and stopwatch
24-hour clock
Between the twelve- and twenty-four-hour clocks, with the whole chart.
It runs entirely in this browser tab: what you type is never uploaded, and the tool makes no network request while it works. Open your browser's network panel and try it — nothing leaves the page. There is no sign-up and no account.
Settings
- Show the whole chart
- All twenty-four hours, for learning rather than converting.
- Show seconds
- Only worth it when the input has them.
How to use it
- Paste your text into the box above, or open a file.
- Adjust the settings beside it until the result is what you wanted.
- Copy the result, or save it as a file. The result updates as you type.
Questions
- Is 03/04/2024 the third of April or the fourth of March?
- Both, and no parser can tell. Every tool that reads a date has a setting for the order, and a four-digit year first is never ambiguous whatever the setting says. The format converter goes further: it counts the dates in a column that can only be read one way, and warns when the column disagrees with itself.
- Are the public holidays accurate?
- They are rules rather than dates — a fixed day, an offset from Easter, or the nth weekday of a month — so they work for any year. They are not a legal source: holidays are moved, added and removed by decree, and regional ones are not here at all. Every result that uses them says so.
- Does it know about time zones?
- No, deliberately. A time-zone database is several megabytes, larger than this whole application, and it is revised several times a year — a stale copy would put a meeting an hour out for half of Europe every spring. The meeting planner takes offsets from you and says it knows nothing about daylight saving.
- Is what I type uploaded anywhere?
- No. This page carries the whole tool as WebAssembly and runs it on your own device. Nothing you type is sent anywhere.
Other tools for clock and stopwatch
Time between times
How long between two times of day, midnight included.
Add up times
A column of durations added or subtracted, with the running total.
Timesheet rounding
Clock-ins rounded to an interval, and which way the total drifted.
Lap times
Laps, splits, the fastest and the slowest, and the pace with them.
All twenty-five tools