Learn about the Gregorian calendar and how it determines the number of days in each month. Find out why only February has 28 days in a common year and how to calculate the days in other months . How many days are there in each month ? With one exception, months have 30 or 31 days —but February lasts for only 28 days in common years and 29 days in leap years. ©timeanddate.com From 10 to 12 Months Our current Gregorian calendar and its predecessor, the Julian calendar, both have 12 months . However, the month names we use today are derived from the Roman calendar, which initially had only 10 months , with the calendar year starting in March (Martius). Calendar with holidays The Romans ... All 12 months have at least 28 days . February is the only month that has exactly 28 days in common years, and 29 days in leap years. So, technically, no months have "only" 28 days , but February is ... How many months during this year can have twenty eight days ? 2016 is a leap year, so there are no months of 28 days . In non-leap years, February has 28 days .
