Nassî': the five or six days that complete the solar year up to the next 21 September; six days when the year contains a 29 February. Placed after Rabi' al-Thani, it extends the inviolable period.
Inviolable period — Muharram, Safar, Rabi' al-Awwal and Rabi' al-Thani, then the Nassî', which follows them and extends the period by five or six days every year.
Twelve months of thirty days, each made of three periods of ten days, and every year a Nassî' of five or six days. The year begins every 21 September, a fixed date next to the autumn equinox, so it does not drift through the seasons. The first day of year 1 is 21 September 621.
Order of the months: Ramadan, Shawwal, Dhu al-Qa'da, Dhu al-Hijja, Muharram, Safar, Rabi' al-Awwal, Rabi' al-Thani, then the Nassî', then Jumada al-Ula, Jumada al-Akhira, Rajab, Sha'ban. The inviolable period runs from Muharram to Rabi' al-Thani, and the Nassî' extends it.
21 September 621 (18 September 621 in the Julian calendar), first day of year 1; every year begins on 21 September.
Dates before Friday 15 October 1582 are given in the Julian calendar then in use (marked "Julian"), later ones in the Gregorian calendar: Thursday 4 October 1582 (Julian) is followed by Friday 15 October 1582 (Gregorian).
Inviolable period — Muharram, Safar, Rabi' al-Awwal and Rabi' al-Thani, then the Nassî', which follows them and extends the period by five or six days every year.
Ramadan — The first month of the year, in a crimson cartouche: it begins on 21 September, near the autumn equinox.
Tens of days — Each month has three periods of ten days (Day 1 to Day 10); the Nassî' stays outside them. The date changes at midnight.