Which isn't all that helpful, as we're never told how long that lunar day is. note The use of 83 is of course a reference to to the fact that that 1983 was the year before the series came out. Apparently, giant shape-shifting robots never bothered with units of time greater than 8.3 minutes and less than 83 years.
The New Krypton story arc has the Kryptonians using a weird time unit, apparently of an order of magnitude similar to the minute.In the Bronze Age, Superman comics stated that Kryptonian time was divided into 'dendars', their equivalent of a minute that consists of one hundred seconds, which implies that Kryptonians were very enthusiastic about the metric system.
