Why does february has 28 or 29 days only?
Why does February have 28 days? Why 29 in leap years?
How many days are in a leap year? Why do months have different number of days? I mean they vary from 28 to 31. Why not have an approximate average? Why don't all months have same number of days? Why does July and August has 31 days? Why do different months have different days? Why do July and August both have 31 days consecutively? Birthdays: What happens to people born on February 29th? Why do July and August have 31 days each? Why, in evolutionary thought, are periods in sync with the moon (28 or 29 days)? If a year contains of 52 weeks, then why did we have 12 months of an unequal number of days rather than 13 months of 4 weeks each? Why aren’t calendars designed with 13 months of 28 days each? What is the probability of having 53 Monday in a leap year? In a non-leap year, which is greater: the mean number of days per month or the median number of days per month? How many days are in a month? Why is 1700 a leap year? How many leap years are there in a century and why? What's the probability that any non-leap year has 53 fridays? Why do the 30 day months go quicker than the 31 day months? What's the probability that a leap year has 53 Sundays? Why isn't there 13 months in a year? Why is January a depressing month? Why will the last minute of June 30, 2015 have 61 seconds? Calendars: Why did September 1752 have fewer days? What's the probability that a leap year has 53 fridays or 53 saturdays? What is the probability to getting 53 Thursday in one leap year? How? Why was the leap year created? What is the probability that a leap year will have 53 Sundays and 53 Mondays? What is a leap year? Why do clocks have 12 hours? What is shortcuts to remember which months has 31 days?