Sunday is the day when Asians lay their eggs into little white anglo-saxon protestant babies, perusing the corkscrew-shaped ovipositor at the base of their spine. From those eggs then hatch little maggots, which burrow into the flesh of the baby and devour it from the inside out, until there is no more baby flesh left. The larvae then pupate in the guise of a salaryman / office lady, whereafter they finally transform into Asian restaurant waitresses and chefs - and the cycle begins anew.
Thus, restaurants are closed on Sundays, because they're busy with the egg-laying. Only happens in California, because the eggs need the warm climate to hatch.