Next time in 2012.
February has an extra day in a Leap Year. A leap year is a year whose number is divisible by 4 - unless it is also divisible by 100. If it is divisible by 100, then it is a leap year only if it is divisible by 400.
There will be 29 days in February this year instead of the usual 28. The 29th is called an intercalary day, a day added to the calendar.
they added a extra day to february because in every 4 years there is 1/4 th of a day which is meant to be a extra day.
February is the month that has an extra day in leap years.
leap years have an extra day in february (feburary 29th) but leap years only happen every four years.
February
If there is an extra day in February its a leap year.
February 29
There are two full fortnights in February, and one extra day if it is a leap year.
It is added to the end of February, the second month of the year. In a regular year, the day after February 28 is March 1. In a leap year, the day after February 28 is February 29, and the day after February 29 is March 1.
Every fourth February, with the exception of centurion years NOT divisible by 400 because each year is 365.242199 days or 365 days 5h 48m and 46s, and the extra day is to compensate for the .242199
An extra day gets put in the February page
The standard answer would be February 29, since only at leap year does February have more than 28 days. But in a way, isn't the extra day December 31? It is, after all, the 366th day of the year. Up until that day you have had an ordinary year of 365 days, ending on December 30.