PureTools
Time Converter
Convert between every time unit instantly, from milliseconds to millennia, and calculate exact durations between two dates. Live grid, no rounding surprises, fully private.
Pick two dates above to see the exact duration between them.
How to use the Time Converter
- Pick a mode, "Convert Units" for unit conversion, or "Duration Between Dates" for calendar differences.
- In Convert mode, type a value (for example, 90) and pick the unit you typed (Minute). Every other unit updates live in the grid below.
- Use the preset chips ("1 day", "1 year", "1 century") for one-tap classic conversions.
- Click Copy result to copy a clean one-liner, or Copy summary to copy the entire grid as plain text.
- In Duration mode, fill the two date pickers. The tool returns the exact calendar breakdown (years, months, days, hours, minutes, seconds) plus the total in every common unit.
Why some units are averages
Months and years vary in length: February is 28 or 29 days, July is 31, a leap year has 366 days. For pure unit conversion, this tool uses the Gregorian averages (1 month = 30.4375 days, 1 year = 365.2425 days), which match the SI standard. If you need exact calendar arithmetic, for instance, "how old am I in months and days?", switch to Duration Between Dates, which counts real months and leap days.
Supported units
- Millisecond, second, minute, hour, standard short-duration units.
- Day, week, month, quarter, common calendar units.
- Year, decade, century, millennium, for historical or long-term durations.
Frequently asked questions
How accurate are the month and year conversions?
Months use the average length of 30.436875 days, and years use the Gregorian average of 365.2425 days. This is the same standard the International System of Units uses for the average calendar year. For exact calendar differences (for example, between 2024-01-15 and 2025-03-30), use the Duration Between Dates mode, which counts real calendar months and leap days correctly. For other physical units like length, weight and temperature, see the Unit Converter.
Why does the converter show every unit at once instead of just one?
Showing every unit simultaneously is faster and more useful than picking a target unit. If you enter 90 minutes, you instantly see it equals 1.5 hours, 5400 seconds, 0.0625 days and so on. The card highlighted in color represents the unit you typed in, so you always know your reference point. If you need to convert a raw Unix epoch integer to a calendar date rather than a duration, use the Epoch Converter.
What is the difference between this tool and the Duration mode?
Convert Units takes a single value and a unit (for example, 5000 minutes) and shows it expressed in every other unit. Duration Between Dates takes two specific points in time (for example, your birthday and today) and computes the elapsed years, months, days, hours, minutes and seconds between them, accounting for variable month lengths and leap years.
Is my data sent to a server?
No. Every calculation runs entirely in your browser using vanilla JavaScript. Nothing you type into the converter is transmitted, logged or stored on any PureTools server. The page works offline once loaded. Google Analytics measures page visits only and Google AdSense serves ads; neither receives your input values. Only the static page files load from PureTools; the actual values you type stay in the current browser tab and disappear with that tab session. Your data is never used to train AI models or improve machine learning systems.
Can I convert very small or very large numbers?
Yes. The tool handles values from picoseconds-scale fractions up to thousands of millennia. Numbers smaller than 0.0001 or larger than one billion are automatically displayed in scientific notation (for example, 1.234 × 10⁻⁶) so the result stays readable. Numbers in between are formatted with thousands separators and smart decimal precision.
How do I calculate how many days are left until a future date?
Switch to the Duration Between Dates tab. Set the From field to today and the To field to your target date, the "Set to now" button fills the current date and time in one click. The result panel shows the exact calendar breakdown: years, months, days, hours, minutes and seconds remaining. This works for countdowns to events, project deadlines, contract renewals, subscription expirations and annual anniversaries where precision matters.
Can I use this tool to convert video or audio durations?
Yes. Enter the total duration of a video or audio file in the value field, for example, 5400 seconds for a 90-minute recording, and every other unit updates instantly. This is useful for content planning (10 hours of footage equals 36,000 seconds), podcasting (comparing episode lengths across formats), streaming (pairing bit-rate with duration for storage estimates) and any production context where you need to quickly move between different time representations without a spreadsheet.