About the d to s calculation
One day is exactly 86,400 seconds, so converting between them is a single multiplication. Enter any value above and the result updates as you type. Twenty-four hours, or 86,400 seconds — one full rotation of the Earth relative to the Sun. The SI base unit of time, defined by the radiation period of the caesium-133 atom.
Formula
s = d × 86,400
1 d = 86,400 s
1 s = 0.00001157 dWorked example
To convert 30 d, multiply by 86,400: 30 × 86,400 = 2,592,000 s.
Frequently asked questions
How many seconds are in a day?
There are 86,400 seconds in one day. To convert any amount, multiply the number of days by 86,400.
How do I convert seconds back to days?
Divide instead of multiplying, or equivalently multiply by 0.00001157. One second is 0.00001157 days.
Is this conversion exact?
For seconds through weeks, yes — they are fixed multiples. The year is the mean Gregorian year of 365.2425 days, which is an average rather than the length of any particular calendar year.
Where is each of these units used?
Days: twenty-four hours, or 86,400 seconds — one full rotation of the Earth relative to the Sun. Seconds: the SI base unit of time, defined by the radiation period of the caesium-133 atom.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units