There are 12 months in a year; There are four quarters in a year (1, and February and March are 1 quarter; April, May and June are the second quarter; July, August and September are the third quarter; 10, 1 1 and 65438+February are the fourth quarter); A normal year has 365 days, 28 days in February, 18 1 day in the first half and 184 days in the second half. The normal year is 52 weeks, 1 day.

Monthly method: 1, 3, 5, 7, 8, 10, wax, 3 1 day is never bad; 4, 6, 9, winter, 30 sharp, only February 289, 7 big months, 4 small months, February 28 days, leap year 29 days; There are 366 days in leap year, 29 days in February, 182 days in the first half and 184 days in the second half. A leap year has 52 weeks and 2 days.