Lailat-al-Miraj marks the night when Prophet Mohammad attained a very high spiritual level and was spiritually transported to heaven. The Ascent took place on the 27th day of Rajab. Although Lailat al Miraj is always on the same day of the Islamic calendar, the date on the Gregorian calendar varies from year to year.
Lailat al Miraj in 2018 is on Friday, the 13th of April.