In the Gregorian calendar, a year y is a leap year if and only if (mod(y,4) == 0) & (mod(y,100) ~= 0) | (mod(y,400) == 0)
Thus 2000 was a leap year, but 2100 will not be a leap year. This rule implies that the Gregorian calendar repeats itself every 400 years. In that 400-year period, there are 97 leap years, 4800 months, 20871 weeks, and 146097 days.
The Matlab functions datenum, datevec, datestr, and weekday use these facts to facilitate computations involving calendar dates. For example, either of the statements [d,w] = weekday('Aug. 17, 2003') and [d,w] = weekday(datenum([2003 8 17])) tells me that my birthday was on a Sunday in 2003. Use Matlab to answer the following questions.
1. On which day of the week were you born?
2. In a 400-year Gregorian calendar cycle, which weekday is the most likely for your birthday?
3. What is the probability that the 13th of any month falls on a Friday? The answer is close to, but not exactly equal to, 1/7.
