For example,
60 seconds = 1 minute
60 minutes = 1 hour
24 hours = 1 day
7 day = 1 week
29-31 days = Month (approx.)
365/366 days = year
It's like for the imperial measurement of distance, where 1 mile = 5280 feet...
Edit: just to clarify, I'm more or less keen towards any consistent, decimal-based measurement systems like base-10 or base-12.
And when you are studying financial mathematics, there 30 days months all around, or not actually each day is counted, or wait it's only work days. For the year you can have 360 days at year, or 365 or sometimes 366. And you need to remember all that shit for tbe exams and never use it again because is the problem for the programmers to solve.
Uh, I think I'm confused by what ye said...