13 months

We came up with a calendar for our Stars Without Numbers campaign. Roughly based on the Terran standard year to keep track of things.
Rounds, minutes, hours, days and weeks as normal, months are all 28 days or 4 weeks and a year is 13 months, 364 days and an even 52 weeks.
This makes things easier by accounting standards and what free merchant wouldn't like that. No the months aren't named just numbered. The year is 3200 Terran standard the campaign date is 6/10/00.