Tonight (23 January) at sunset the holiday of Eid Al Mawled commences. This means tomorrow (24 January) is a holiday. This usually only affects the public offices and banks but some local shops may also close.
Eid Al Mawled celebrates the Prophet Muhammed's Birth and the celebrations are predominately for the Sunni community (the Shi'a celebrate this next Tuesday the 29th). The celebrations are quite random and can range from street celebrations to family feasts. Those who chose to celebrate will almost certainly include attendance at the local mosque and Koran reciting.
The birth of the prophet Muhammad is generally regarded as the most significant event in Islamic history, but not everyone agrees that the event should be celebrated as Muhammad's companions did not observe the event, and Muhammad also did not observe anniversaries within his own family.
In Marrakech the schools are closed and therefore there is a greater presence of children playing and jollity in the streets.