60 seconds (sec.) = 1 minute (min.)
60 minutes = 1 hour (hr.)
24 hours = 1 day (da.)
7 days = 1 week (wk.)
30 days = 1 commercial month (mo.)
52 weeks = 1 year (yr.)
12 months = 1 year
360 days = 1 commercial year
365 days = 1 common year
366 days = 1 leap year
100 years = 1 century
Century Years Months Days Hours Minutes
1 = 100 = 1,200 = 36,500 = 876,000 = 52,560,000
Centennial years exactly divisible by 400, and other years exactly
divisible by 4, are _Leap Years_.