AnyTool
Your files never leave your device. All processing happens locally in your browser.

How do I convert time between seconds, minutes, hours, days and years?

Type a value into AnyTool Time Converter and pick the units. It instantly converts between nanoseconds, milliseconds, seconds, minutes, hours, days, weeks, fortnights, months and years both ways, and shows the value in every unit at once in a copyable table. Everything is calculated in your browser, so nothing is uploaded.

  • Live two-way conversion — type in either field and the other updates
  • Fourteen units from nanoseconds and milliseconds up to centuries and millennia
  • See the value in every unit at once, each row copyable
  • Months and years use the average Gregorian length and are clearly labelled
  • 100% in your browser — no upload, no signup, works offline

What is

Time Unit Conversion

Time unit conversion changes a duration from one unit to another — for example hours to minutes. Each unit is expressed as a fixed number of seconds, so any unit converts to any other through a second base. Short units (second, minute, hour, day, week) are exact, while month and year use the average Gregorian length because real calendar months and years vary.

Converters

Related terms

Seconds to minutesHours to daysDays to yearsMilliseconds

Frequently Asked Questions

An hour is 3,600 seconds, a day is 86,400 seconds, and a week is 604,800 seconds.

A minute is 60 seconds, so an hour is 60 × 60 = 3,600 seconds. A day is 24 hours, which is 86,400 seconds, and a week is 7 days, or 604,800 seconds. AnyTool Time Converter uses these exact factors through a second base, and a fortnight (14 days) is 1,209,600 seconds.

On average about 31,556,952 seconds, using the Gregorian year of 365.2425 days.

A calendar year is 365 or 366 days, so there is no single exact answer. AnyTool uses the average Gregorian year of 365.2425 days, which is 31,556,952 seconds, and an average month of one twelfth of that — 30.436875 days, or 2,629,746 seconds. These averages are accurate for durations and rates but are not a substitute for true calendar-date math.

Because real months are 28-31 days and years are 365 or 366 days, so it uses the Gregorian average.

A month can be 28, 29, 30 or 31 days and a year can be 365 or 366 days, so converting them to seconds requires a convention. AnyTool uses the average Gregorian length — 365.2425 days per year and exactly one twelfth of that per month — and labels these units "(avg)" so the approximation is clear. Decade, century and millennium are multiples of that average year.

No. Every calculation runs in your browser, so nothing is sent to a server and it works offline.

AnyTool Time Converter computes every result locally in JavaScript using fixed factors through a second base. No value is uploaded, there is no tracking, and the page keeps working offline after the first load.

Detailed Explanation

Methodology

How the Time Converter Works

AnyTool Time Converter performs every calculation in the browser. Each unit declares how many seconds it equals, so any unit converts to any other through a shared second base without an N-by-N formula table. A minute is 60 seconds, an hour is 3,600, a day is 86,400, a week is 604,800 and a fortnight is 1,209,600 — all exact. Months and longer units use the average Gregorian year of 365.2425 days (31,556,952 seconds), with a month being one twelfth of that (2,629,746 seconds), and decade, century and millennium are 10, 100 and 1,000 of those years.

  • Fourteen units: nanosecond through millennium
  • Second is the shared base; each unit is a fixed factor in seconds
  • Short units (second to fortnight) are exact by definition
  • Month, year, decade, century and millennium use the average Gregorian length
  • All arithmetic is client-side JavaScript — no server round-trip
How It Works

Why Month and Year Are Averages

A real calendar month is 28, 29, 30 or 31 days and a year is 365 or 366 days, so there is no single exact number of seconds for either. AnyTool uses the average Gregorian year of 365.2425 days and exactly one twelfth of that per month, and labels these units "(avg)" so the approximation is explicit. These averages are accurate for measuring durations and rates, but they are not a substitute for true calendar-date arithmetic, which must account for the specific months, leap years and time zones involved.

  • Calendar months vary (28-31 days); years vary (365 or 366 days)
  • Year = 365.2425 days (Gregorian mean) = 31,556,952 seconds
  • Month = year / 12 = 30.436875 days = 2,629,746 seconds
  • Average units are labelled clearly in the interface
  • For exact dates, use calendar-date math rather than averages
Privacy & Security

All Units, Precision and Privacy

A single input is converted into every unit at once in a copyable table, with the source and target rows highlighted. A decimals control sets precision, and magnitudes that are very large or very small automatically switch to scientific notation so results stay readable. Because all conversion runs in the browser, no value is sent to a server, there is no account or tracking, and the page works offline after first load. The converter is built on a shared, unit-tested engine that other AnyTool unit converters reuse.

Time conversion: in-browser (AnyTool) vs typical online converters
CapabilityAnyToolTypical online converters
ProcessingRuns in your browserOften server-side
UnitsNanosecond to millennium (14)Often seconds to years only
Two-way inputEdit either field, both updateUsually one-direction with a button
All units at onceYes, copyable tableOften one target at a time
Month/year honestyLabelled average GregorianOften unlabelled or inconsistent
Works offlineYes (PWA)No
Cost / signupFree, no signupOften ad-heavy or gated

AnyTool converts every unit locally through a second base and uploads nothing.