Ethan Marks

Units of Time

You probably know that a fortnight is equal to 14 days.

However, you probably didn’t know that there are a bunch more units like that. mostly Ancient Roman.

Here’s a list of a few of my favorites:

UnitValueUsage/Source/Trivia
Jiffy1/60 or 1/50 secondsThe frequency of most alternating current power supplies
Punct15 Minutes1/4 of an hour
Mileway20 MinutesThe approximate time it takes to walk a mile
Watch4 HoursA British Naval term where a day was divided into 6 watches
Nundine9 DaysAncient Roman market was held every 9 days
Tredecium13 DaysSome ancient calendar systems were 13-day weeks
Quarantine40 DaysItalian sailors had to stay isolated for 40 days if their ship had a plague
Olympiad4 YearsAncient Roman Olympics were held every four years (modern Olympics are too!)
Lustrum5 YearsAncient Roman population census was taken every 5 years
Indiction15 YearsAncient Romans used it for tax cycles

~Ethan