How to convert time units
1 minute = 60 seconds, 1 hour = 3,600 seconds, 1 day = 86,400 seconds and 1 week = 7 days. Months and years vary in length, so this converter uses Gregorian averages: 1 year = 365.2425 days and 1 month = 1/12 of a year = 30.436875 days. A separate “common year” of exactly 365 days is included.
To add or subtract times, or to find the time between two dates, use the Time Calculator, Hours Calculator or Age Calculator.
Common time conversion factors
| Unit | Equals | Reverse |
|---|---|---|
| 1 hour | 60 min | 1 minute = 0.0166666667 h |
| 1 minute | 60 s | 1 second = 0.0166666667 min |
| 1 day | 24 h | 1 hour = 0.0416666667 d |
| 1 week | 7 d | 1 day = 0.1428571429 wk |
| 1 year (average) | 365.2425 d | 1 day = 0.002737907 yr |
| 1 month (average) | 30.436875 d | 1 day = 0.0328548841 mo |
| 1 hour | 3,600 s | 1 second = 0.0002777778 h |
| 1 millisecond | 0.001 s | 1 second = 1,000 ms |
| 1 year (average) | 8,765.82 h | 1 hour = 0.0001140795 yr |
| 1 day | 1,440 min | 1 minute = 0.0006944444 d |
| 1 decade | 10 yr | 1 year (average) = 0.1 dec |
Time conversions
Each of these has its own page with the formula, worked examples and a full conversion table:
All time units on this converter
| Unit | Symbol | 1 unit equals | System |
|---|---|---|---|
| Nanosecond | ns | 1 × 10⁻⁹ s | Short |
| Microsecond | µs | 0.000001 s | Short |
| Millisecond | ms | 0.001 s | Short |
| Second | s | 1 s | Short |
| Minute | min | 60 s | Short |
| Hour | h | 3,600 s | Short |
| Day | d | 86,400 s | Calendar |
| Week | wk | 6,04,800 s | Calendar |
| Fortnight | fn | 12,09,600 s | Calendar |
| Month (average) | mo | 26,29,746 s | Calendar |
| Year (average) | yr | 3,15,56,952 s | Calendar |
| Common year (365 days) | yr | 3,15,36,000 s | Calendar |
| Decade | dec | 31,55,69,520 s | Long |
| Century | c | 3,15,56,95,200 s | Long |
| Millennium | ka | 31,55,69,52,000 s | Long |
Frequently asked questions
How many seconds are in a day?
86,400 seconds (24 × 60 × 60).
How many days are in a year?
A common year has 365 days and a leap year 366. The average Gregorian year is 365.2425 days, which this converter uses for “year”.
How many hours are in a month?
About 730.5 hours on average (30.44 days × 24). A 30-day month has 720 hours; a 31-day month has 744.