Convert Months to Synodic Months
Convert Months (mo) to Synodic Months (syn.mo) instantly and accurately.
Conversion Formula
syn.mo = mo × 1.030689742
About Months
A mean Gregorian calendar month = 365.2425 ÷ 12 = 30.436875 days = 2,629,746 s exactly (averaged over the 400-year cycle with exactly 97 leap years). Individual months have 28-31 days. Loan schedules, subscriptions, and mobile billing reference 'per month', requiring explicit agreement on meaning. ISO 8601 uses 'P1M'. 1 mo = 30.436875 d = 2,629,746 s.
About Synodic Months
A synodic (lunar) month = new moon to new moon = 29.5306 days = 2,551,442.9 s. Longer than the sidereal month (27.32 d) because Earth advances ~27° in its orbit during that time; the Moon must travel further to realign with the Sun. Islamic Hijri, Hebrew lunisolar, and Chinese calendars are built on synodic months. Eclipses repeat via the Saros cycle (18 yr 11 d = 223 synodic months). 1 syn.mo ≈ 29.5306 d.
Quick Reference Table
| Months (mo) | Synodic Months (syn.mo) |
|---|---|
| 1 mo | 1.03069 syn.mo |
| 2 mo | 2.06138 syn.mo |
| 5 mo | 5.15345 syn.mo |
| 10 mo | 10.3069 syn.mo |
| 25 mo | 25.7672 syn.mo |
| 50 mo | 51.5345 syn.mo |
| 100 mo | 103.069 syn.mo |