Definition:Calendar/Muslim
Definition
The Muslim calendar is a calendar whose period is based on $12$ full cycles of phases of the moon.
Each Muslim year lasts either $354$ or $355$ days, depending on precisely when the relevant new moons happen
The years are numbered from the year when Muhammad and his followers migrated from Mecca to Medina in $622 \, \text{A.D}$ by the Julian calendar.
Years are denoted with the suffix $\text{A.H.}$, meaning Anno Hegirae, literally in the year of the Hejira.
The start and end of the Muslim year are $10$ to $12$ days earlier every civil year.
The $354$ or $355$ days in the Muslim year are divided into $12$ approximately equal sections called months, each either $29$ or $30$ days, depending on the phases of the moon.
They are assigned both names and index numbers:
| \(\ds 1:\) | \(\) | \(\ds \) | Muḥarram | |||||||||||
| \(\ds 2:\) | \(\) | \(\ds \) | Ṣafar | |||||||||||
| \(\ds 3:\) | \(\) | \(\ds \) | Rabī‘ al-awwal | |||||||||||
| \(\ds 4:\) | \(\) | \(\ds \) | Rabī‘ ath-thānī | |||||||||||
| \(\ds 5:\) | \(\) | \(\ds \) | Jumādá al-ūlá | |||||||||||
| \(\ds 6:\) | \(\) | \(\ds \) | Jumādá al-ākhirah | |||||||||||
| \(\ds 7:\) | \(\) | \(\ds \) | Rajab | |||||||||||
| \(\ds 8:\) | \(\) | \(\ds \) | Sha‘bān | |||||||||||
| \(\ds 9:\) | \(\) | \(\ds \) | Ramaḍān | |||||||||||
| \(\ds 10:\) | \(\) | \(\ds \) | Shawwāl | |||||||||||
| \(\ds 11:\) | \(\) | \(\ds \) | Dhū al-Qa‘dah | |||||||||||
| \(\ds 12:\) | \(\) | \(\ds \) | Dhū al-Ḥijjah |
Muslim Year
A Muslim year, also known as the Islamic year or Hijra year, is the length of a year as defined using the Muslim calendar.
- $1$ Muslim year $= \begin{cases} 355 \, \text {days} & : \text {Leap year} \\
354 \, \text {days} & : \text {Non-leap year} \end{cases}$
Also known as
The Muslim calendar is also known as the Hijri calendar or the Islamic calendar.
Sources
- 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $365 \cdotp 2422$
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $365 \cdotp 24219 \, 878$