One year has approximatly 52 weeks. One calendar common year has 365 days: 1 common year = 365 days = (365 days) / (7 days/week) = 52.143 weeks = 52 weeks + 1 day. One calendar leap year occures every 4 years, except for years that are divisable by 100 and not divisable by 400.

One calendar leap year has 366 days, when February has 29 days: 1 leap year = 366 days = (366 days) / (7 days/week) = 52.286 weeks = 52 weeks + 2 days. This is viable to anyone, thus we can calculate easily the days, hours, weeks, seconds, and etc.