Board Thread:Fantasy Universe Discussion/@comment-1309126-20140823154850/@comment-26127592-20150220033752

You should base universal calendars not on solar, stellar or planetary movements, but on atomic movements, chemical decay, or something with a reliable rhythm. Moons, planets, stars and other galactic objects can shift in orbit; slowing down, speeding up, crashing into other objects. Atomic movement or decay or whatever ticks at a constant rate. If you need exact measurements, look it up.