Meliora's 25 man raid schedule is currently the following (all times server):

Sunday 7:30 PM to 11PM
Tuesday 7:30 PM to 11PM
Wednesday 7:30 PM to 11PM

Be prepared, and be on time!

Which raid we go to on a particular day will generally be announced the night of the raid.

10-man raids and older content such as Naxx, Obsidian Sanctum, and Malygos are run as demand warrants.