Convert time units: Seconds (s) ↔ Fortnights (14 days) — with shake (10⁻⁸ s) unit reference for nuclear physics, astronomy, and everyday time calculations.
Select conversion direction:
Time Conversion Formula (SI & Custom Units):
1 Fortnight = 1209600 Seconds | 1 Second = 8.267195767×10⁻⁷ Fortnights | 1 Shake = 10⁻⁸ Seconds
fn = s ÷ 1209600 | s = fn × 1209600 | shake = s × 10⁸ (Results: 6 decimal places for seconds/fortnights)
*SI definition: Fortnight = 14 days (custom time unit) | "Shake" = 10⁻⁸ s (informal unit for nuclear physics)
SI base unit of time: Used in physics, engineering, everyday timekeeping, nuclear reactions (shake unit reference)
Display format:
Quick conversions (common time values) - click to auto-fill:
Useful for time calculations? Share with scientists, astronomers, or anyone needing second/fortnight conversions:
Understanding time units for physics, astronomy, nuclear science, and everyday use.
| Unit | Symbol | Conversion Factor | Common Uses |
|---|---|---|---|
| Shake | sh | 1 sh = 10⁻⁸ s = 8.267195767×10⁻¹⁵ fn | Nuclear physics (measure reaction times), high-speed experiments |
| Second | s | 1 s = 10⁸ sh = 8.267195767×10⁻⁷ fn = 1/3600 h | SI base unit of time, physics, engineering, everyday timekeeping, computing |
| Fortnight | fn | 1 fn = 14 days = 1209600 s = 1.2096×10¹³ sh | Astronomy, payroll (biweekly), historical timekeeping, UK/commonwealth usage |
| Seconds (s) | ≈ | Fortnights (fn) | Application |
|---|---|---|---|
| 1 | ≈ | 0.000000826720 | Basic time unit (1 shake = 10⁻⁸ of this) |
| 86400 | ≈ | 0.07142857 | One day (24 hours = 86400 seconds) |
| 604800 | ≈ | 0.50000000 | One week (7 days = half a fortnight) |
| 1209600 | ≈ | 1.00000000 | One fortnight (14 days = 2 weeks) |
| 31536000 | ≈ | 26.088722 | One year (365 days, approximate) |
Time units span extreme ranges—from subatomic shakes to biweekly fortnights:
| Unit | Symbol | Equivalent to 1 Second | Use Case |
|---|---|---|---|
| Shake | sh | 1 s = 100,000,000 sh | Nuclear reaction times, particle physics |
| Millisecond | ms | 1 s = 1,000 ms | Computer processing, human reaction time |
| Second | s | 1 s = 1 s | Everyday timekeeping, SI base unit |
| Fortnight | fn | 1 s = 8.267196×10⁻⁷ fn | Biweekly payroll, astronomical calculations |
About seconds, fortnights, shakes, and time unit conversions
The conversion factor comes from the definition of a fortnight (14 days) and standard time units:
Precise factor: 1 fn = 1209600.0 s (exact for all time calculations)
Practical use: 6 decimal places suffice for everyday use; scientific use may need more
A "shake" is an informal (non-SI) time unit with a critical niche in nuclear physics:
Use these cross-unit conversion factors for full time scale compatibility:
1 Fortnight (fn) = 14 Days = 336 Hours = 20160 Minutes = 1209600 Seconds = 1.2096×10¹³ Shakes
1 Second (s) = 1/60 Minutes = 1/3600 Hours = 1/86400 Days = 8.267195767×10⁻⁷ Fortnights = 10⁸ Shakes
1 Day = 86400 s = 0.07142857 fn | 1 Hour = 3600 s = 2.976190476×10⁻⁶ fn
Practical cross-conversion examples:
These conversions are useful for payroll (biweekly = fortnightly), astronomy (long-term time scales), and physics (short-term reaction times).
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