⏱️ Time Unit Converter
Convert between seconds, minutes, hours, days and more.
Why Time Conversions Are Not All Exact
Time units are mostly fixed multiples: 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day and 7 days in a week. Months and years are the exception — a calendar month has 28 to 31 days and a year has 365 or 366 — so a converter has to pick a convention. This tool uses a 30-day month and a 365-day year, the convention most financial and scientific calculations follow.
Conversion Reference
Multiply along the factor chain: hours × 3,600 = seconds, days × 86,400 = seconds, years × 31,536,000 = seconds. A leap year adds 86,400 seconds, so long spans should be computed from actual calendar dates instead.
Worked Examples
2.5 hours = 2.5 × 3,600 = 9,000 seconds
90 days = 90 ÷ 30 = 3 months (30-day convention) = 7,776,000 seconds
Where the 30-Day Month Matters
A 30-day month is a convention, not a calendar fact. Applying it to contracts, interest, payroll or leave accrual can be off by up to a day per month, which is why finance uses actual/365 or 30/360 day-count rules. For calendar questions, use a date calculator rather than multiplying units.
Frequently Asked Questions
- How many seconds are in a day?
- 86,400 — that is 24 × 60 × 60.
- How many weeks are in a year?
- 52 weeks plus one day, or two in a leap year. That is why a fixed date falls on the next weekday each year.
- Why does a month count as 30 days here?
- Because calendar months vary, multiplication needs a fixed value. 30 days is the common convention; use a date calculator when the exact calendar month matters.