Legion Standard Time is the date kept by the Legion since its creation. The actually timekeeping itself is done by the Generator at the center of the Worldship. It was established by the Watchmaker, who understood the value of recordkeeping and history.
The L.S.T. operates on a 25-hour day and a 500 day year. Each year is divided into "Sets", each one hundred days long and equivalent to "months".
The standard notation is written as day/set/year.