Sunday Specials are limited dishes that are released on Sundays and can be unlocked during short periods of time only. It was first released on March 13, 2011.
Originally, Sunday Specials were only available the day they were released (i.e. during 24 hours). However, their availability has been extended afterwards in order to help players to get them. Thus, since May 1, 2011 Sunday Specials are released for either 36 or 48 hours (i.e. until noon or midnight on Monday).