According to tradition Ashtanga yoga (asana practice) is practised six days a week, with one day off on Saturday or Sunday. Rest is also taken on new and full moon days. When asana practice is done daily, rest days are necessary for regeneration and the extra biweekly "moon days" are important to observe for that reason. For more about the history around full/new moon days please check here.
Regular Mysore classes will be cancelled on the following full and new moon days (only beginners courses run as usual unless the teacher informs otherwise):