Timecon - Time Conversion Tool
Timecon converts a length of time from one unit to another as you type. Enter a value, choose the unit you have and the unit you want, and the answer appears straight away, from nanoseconds and microseconds up to decades and centuries.
It is useful when the numbers get awkward: turning a 2,700,000-millisecond timeout into minutes, working out how many hours are in six weeks, or checking how many seconds there are in a year for a physics exercise. Developers, students and anyone planning long projects tend to need these conversions more often than they expect.
Alongside the converter, the page has a simple countdown timer, a world clock with a time-difference calculator, a short guide to time units and a list for your own custom units. It runs in your browser with no account.
The app runs entirely in your browser. What you enter is saved only on this device.
How to use Timecon
- Enter a value. On the Convert tab, type a number into the input box. Decimals are allowed.
- Pick the units. Choose the From and To units from the menus. Tap the swap button between them to reverse the direction.
- Read and copy the result. The result card shows the conversion immediately. Tap the copy icon to copy it.
- Keep a history. Press Enter after typing to save the conversion to the History tab, which keeps your latest 20 conversions for this visit. Clear it with the delete button.
- Use the timer. On the Timer tab, add or remove time in one-minute steps, then start, pause or reset the countdown. A circular gauge shows the remaining time.
- Compare time zones. The Time Zones tab shows a clock for several world cities and a calculator for the time difference between two of them.
- Add custom units. On the Custom tab, define a unit such as a 45-minute class period by giving it a name and a length in milliseconds, for quick reference.
Features
- Converts between 12 units from nanoseconds to centuries
- Instant results with a swap button
- Copy the result to the clipboard
- History of the last 20 conversions during your visit
- Countdown timer with a circular gauge
- World clock and time-difference calculator
- Custom unit list
- Info tab with a summary of time units and trivia
Understanding units of time
The fixed units
The second is the base unit of time in the International System of Units, defined by an atomic property of caesium. From there, the smaller units step down by factors of one thousand: a millisecond is a thousandth of a second, a microsecond a millionth and a nanosecond a billionth. Going up, a minute is 60 seconds, an hour 3,600 seconds, a day 86,400 seconds and a week 604,800 seconds. These relationships are exact, so conversions between them are precise.
Months and years are averages
Calendar months range from 28 to 31 days, and a calendar year is 365 or 366 days. Any converter therefore has to choose a convention. Timecon uses a 30-day month and a 365-day year (so a decade is 3,650 days and a century 36,500 days). That is convenient for estimates, but it differs slightly from other conventions such as the Julian year of 365.25 days used in astronomy or the average Gregorian year of 365.2425 days. For contracts, interest or ages, count actual calendar dates instead.
Where small units matter
Milliseconds appear constantly in computing: timeouts, animation durations and response times are usually given in ms. Microseconds and nanoseconds describe how long processor operations or signals in a cable take; light travels about 30 centimetres in a nanosecond. When you see very large millisecond values, such as 86,400,000, converting them to hours or days is the quickest sanity check.
A quick mental toolkit
Useful round numbers: there are about 31.5 million seconds in a year, 525,600 minutes in a 365-day year and 8,760 hours. One million seconds is about 11.6 days, and one billion seconds is roughly 31.7 years.
For quick checks, remember that a week is 168 hours and that a 30-day month is 720 hours. Converting to the next-larger unit and rounding is usually enough to spot a misplaced zero before it causes a bug or a scheduling mistake.
Frequently asked questions
How long is a month or a year in Timecon?
A month is treated as 30 days and a year as 365 days. Decades and centuries are 10 and 100 of those years.
Is my history saved?
Only while the page is open. History and custom units are cleared when you reload or close the page.
Are the world clock times adjusted for daylight saving time?
No. The world clock uses fixed hour offsets and does not follow daylight-saving changes, so use it as a rough guide and check an official source for meetings or travel.
Does the timer sound an alarm?
It counts down on screen while the page is open; it can't alert you after the page is closed.
What is different from the phone app?
The tools are the same. The iPhone and Android apps show ads that a subscription removes; the web version has no ads or purchases.
Limitations of the web version
- Months are 30 days and years 365 days
- History and custom units are not kept after reloading
- Custom units are a reference list and can't be chosen in the converter
- World clock uses fixed offsets from Japan time and ignores daylight saving time
Phone app
Timecon is also available as an app for phones and tablets: