The second is the SI base unit of time.
Seconds to Days Converter — s to d
Convert Seconds (s) to Days (d) using the exact conversion factor (1 seconds = 0.0000115741 days). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Seconds to Days converter
Converter
Astronomy Converter
Convert astronomical length, mass, time, and distance units by compatible family.
Context values
Some unit families need one extra value for a physically accurate result.
A day is 86,400 seconds.
Result = input x 1 / 86400.
Time units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Seconds to Days
Seconds and Days both describe astronomical distances at very different scales — one for measuring within our solar system, the other for the distances between stars — and converting between them helps put the scale of space into perspective. Seconds is most often used for fundamental unit for all timekeeping and scientific measurement.
Formula
days = seconds × 0.0000115740740741
This factor comes from each unit's defined relationship to the category's base unit: 1 seconds equals 1 base unit, and 1 days equals 86400 base units, so dividing one by the other gives the direct seconds-to-days factor of 0.0000115740740741.
Simple example
1 s × 0.00001157407407 = 0.0000115741 d
1 seconds = 0.0000115741 days.
Real-world example
4.24 s × 0.00001157407407 = 0.0000490741 d
4.24 seconds = 0.0000490741 days.
Conversion table
| Seconds (s) | Days (d) |
|---|---|
| 1 s | 0.0000115741 d |
| 4.24 s | 0.0000490741 d |
| 10 s | 0.0001157407 d |
| 100 s | 0.0011574074 d |
| 1,000 s | 0.0115740741 d |
| 1,000,000 s | 11.57407407 d |
Reverse conversion: Days to Seconds
0.0000115741 d × 86400 = 1.00000224 s
0.0000115741 days = 1.00000224 seconds.
seconds = days × 86400
For a page dedicated to this direction, see Days to Seconds.
Seconds vs. Days
| Aspect | Seconds | Days |
|---|---|---|
| Family | SI base unit | Non-SI unit accepted for use with SI |
| Typical use | Fundamental unit for all timekeeping and scientific measurement | Calendars and scheduling worldwide |
| Where it's used | Universal | Universal |
Understanding the Seconds
Seconds (s) measures time. The second is the SI base unit of time, currently defined via a fixed number of cesium atomic transitions. It is classified as a SI base unit.
Where it's used: Universal
Uses of the Seconds today
- Fundamental unit for all timekeeping and scientific measurement
- Basis for derived units like speed (m/s) and frequency (Hz)
History of the Seconds
The second originated from dividing the day into 24 hours, each into 60 minutes, each into 60 seconds — a sexagesimal (base-60) system inherited from Babylonian astronomy. Since 1967, the second has been defined atomically, as exactly 9,192,631,770 periods of radiation from a cesium-133 transition, decoupling timekeeping from the Earth's slightly irregular rotation.
Historical origin. Seconds was not the invention of a single named person; it developed through the process described above.
Understanding the Days
Days (d) measures time. A day is defined as exactly 86,400 seconds (24 hours), approximating one rotation of the Earth. It is classified as a Non-SI unit accepted for use with SI.
Where it's used: Universal
Uses of the Days today
- Calendars and scheduling worldwide
- Age, tenure, and duration calculations
- Project planning and deadlines
History of the Days
The day as a natural unit (one Earth rotation) is prehistoric in origin; its fixed 86,400-second definition follows from the standardized hour, minute, and second, decoupling the calendar day slightly from the actual (very gradually lengthening) astronomical day.
Historical origin. Days was not the invention of a single named person; it developed through the process described above.
Seconds — sources
- BIPM — The second (SI base unit) — Current atomic definition and history of the second.
Days — sources
- BIPM SI Brochure — Non-SI units accepted for use with SI — Lists the day among accepted non-SI time units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many days are in 1 seconds?
1 seconds equals 0.0000115741 days, using the exact defined conversion factor rather than an estimate.
How do I convert seconds to days?
Multiply the seconds value by 0.00001157407407. The converter above does this instantly to whatever precision you set.
How do I convert days back to seconds?
Use the reverse factor: 1 days equals 86,400 seconds. You can also use the swap control in the converter above to flip the direction instantly.
What is a seconds?
Seconds (s) measures time. The second is the SI base unit of time, currently defined via a fixed number of cesium atomic transitions. It is classified as a SI base unit.
What is a days?
Days (d) measures time. A day is defined as exactly 86,400 seconds (24 hours), approximating one rotation of the Earth. It is classified as a Non-SI unit accepted for use with SI.
Is the seconds to days conversion exact?
Yes. A day is defined as exactly 86,400 seconds (24 hours), approximating one rotation of the Earth. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
Where is the seconds still used today?
Universal