While some Saturday Night Live writers begin writing immediately after Monday’s Pitch session, most of the writers start working on Tuesday. From here on out, staffers are in a race against time- all of the sketches approved at the Monday Pitch session are supposed to be completed by Wednesday. This often leads to the writers and cast pulling all-nighters to get the sketches finished in time.
If a potential Sketch requires an elaborate set, it is typically due on Tuesday to give the set decorators a head start and begin working on building the set. Additionally, any sketch requiring pre-filming also has a Tuesday deadline so that the crew can begin figuring out the logistics. In any case, the sketches being written today will be seen by millions in just a few days.