Sheldon is watching the premiere episode of Star Trek: Deep Space Nine (1993): Emissary (1993), which sets this episode's date as the week of January 3, 1993.
Sheldon's reaction to his mom making pancakes on Sunday is very reminiscent of The Big Bang Theory (2007): The Gothowitz Deviation (2009), when Penny offers to make him French Toast and he tells her no, because it's his morning to eat oatmeal.