Al-Mutawakkil Alallah was the 24th Sultan of Johor. He died on January 22nd 2010. It is the custom that the date of the passing of the previous Sultan is observed as a public holiday in the Malaysian state of Johor.
The anniversary of his death is based on the Islamic calendar. January 22nd 2010 was 6 Safar 1431. As the Islamic calendar is based on the lunar calendar, this date moves forward in the western calendar by about 12 days each year.
The tradition of honouring the previous Sultan dates back to the first ruler of modern Johor who died in 1895.
