Convert Sidereal Months to Centuries
Convert Sidereal Months (sid.mo) to Centuries (cent) instantly and accurately.
Conversion Formula
cent = sid.mo × 0.0007480416898
About Sidereal Months
The sidereal month = Moon's orbital period relative to the fixed stars = 27.3217 days = 2,360,591.6 s - the shortest lunar month. It is ~2.21 days shorter than the synodic month (29.53 d) because Earth advances ~27° along its orbit in the same period; the Moon must travel further to re-align with the Sun. Used in GPS orbit design, tidal modelling, and lunar laser ranging. 1 sid.mo = 27.3217 d.
About Centuries
A century = exactly 100 Gregorian years ≈ 3.156 × 10⁹ s. Standard unit of historical periodisation (the 20th century, the 18th-century Enlightenment). IPCC projects warming and sea-level rise on century timescales. Precession of the equinoxes advances ~1.39°/century, so zodiac constellations no longer match their named seasons. Ice-core and radiocarbon records are commonly displayed at century resolution. 1 century = 100 yr.
Quick Reference Table
| Sidereal Months (sid.mo) | Centuries (cent) |
|---|---|
| 1 sid.mo | 0.000748042 cent |
| 2 sid.mo | 0.00149608 cent |
| 5 sid.mo | 0.00374021 cent |
| 10 sid.mo | 0.00748042 cent |
| 25 sid.mo | 0.018701 cent |
| 50 sid.mo | 0.0374021 cent |
| 100 sid.mo | 0.0748042 cent |