Friday evenings on the way home from work are often helpful. Failing that, if you're either not a party time type person or if your party time starts later than the average, 6pm-ish on Saturday used to work for me (granted, at that time I lived in a town that was half snooty yuppies and half pain-in-the-ass college kids, and I belonged to both groups at some point during my residence there). So for what that's worth :)

Another thing I do to keep myself from wasting food--and to make sure I shop regularly--is only buy enough food for the week. I keep some things in stock, like pasta and rice and a few cans of soup for emergencies, but my freezer is too small to store a lot of meat/veggies, so I tend to plan out the meals for each week and shop accordingly. (Side benefit: rarely looking at the fridge and going "er, I'm not sure what this science project started life as, but...")