Pancake Day (aka Shrove Tuesday) is not on the same date each year (though it is always on a Tuesday). The actual date it falls on depends on a complicated set of rules described in the formula xy{a}/x%19*syR-up+3 where x is the relative brightness of the first full moon before Easter. Consequentially, it takes 2.8 Flipaflops of processing power to calculate the answer. Thatâ€™s equivalent to roughly 15 million bitgrams or 18,000 data-ounces.