In the West, this era is most commonly denoted as AH (Latin: Anno Hegiraeiː/, "in the year of the Hijra") in parallel with the Christian (AD), Common (CE) and Jewish eras (AM) and can similarly be placed before or after the date. In Muslim countries, it is also commonly abbreviated H ("Hijra") from its Arabic abbreviation hāʾ (هـ). Years prior to AH 1 are reckoned in English as BH ("Before the Hijra"), which should follow the date.
Because the Islamic lunar calendar has only 354 or 355 days in its year, it slowly rotates relative to the Gregorian year. The year 2019 CE corresponds to the Islamic years AH 1440 – 1441. AH 1440 corresponds to 2018 – 2019 in the Common Era.[a]
The date of the Hijra itself did not form the Islamic New Year. Instead, the system continues the earlier ordering of the months, with the Hijra occurring around the 8th day of Rabi al-Awwal, 66 days into the first year.