e number of hours H of daylight in Madrid as a function of date is approximated by the formula ere t is the number of days since the start of the year We can think of t 0 as the stroke of midnight on Dec 31 Jan 1 thus January falls between t 0 and t 31 February falls between t 31 dt 59 etc nd the average number of hours of daylight in Madrid assuming in each case that it is not a leap year in February average hours in July average hours H 12 2 4 sin 0 0172 80 over a year average hours