Day to Second (d to s)
Result
86,400 Second
Formula
s = d × 86,400
1 d = 86,400 s, and 1 s = 0.000011574074 d.
The second is the SI base unit, defined by a caesium-133 transition frequency. Minutes, hours, days and weeks are exact multiples. Month and year here are Gregorian averages: a year of 365.2425 days and a month of one twelfth of that (30.436875 days).
Worked examples
- 1 d × 86,400 = 86,400 s
- 10 d × 86,400 = 864,000 s
- 100 d × 86,400 = 8,640,000 s
Common mistakes
- Calendar months run from 28 to 31 days, so "3 months" from a given date is not 3 × 30.44 days. Use a date calculator for deadlines.
- A 365-day year, a 365.25-day Julian year and the 365.2425-day Gregorian year differ; interest and astronomy calculations specify which one they use.
Day to Second table
| Day (d) | Second (s) |
|---|---|
| 1 | 86,400 |
| 2 | 172,800 |
| 5 | 432,000 |
| 10 | 864,000 |
| 20 | 1,728,000 |
| 50 | 4,320,000 |
| 100 | 8,640,000 |
| 1,000 | 86,400,000 |
The units
- Day (d)
- 1 Day = 86,400 Second.
- Second (s)
- A unit of time.
Sources for these factors
- The International System of Units (SI Brochure), 9th edition — BIPM
- Guide for the Use of the International System of Units (SP 811), Appendix B: conversion factors — NIST
Last reviewed against these sources. An automated check recomputes every factor from its definition on each build. How we check accuracy