This function calculates a date specified by year, month, day and displays it in the cell's formatting. The default format of a cell containing the DATE function is the date format, but you can format the cells with any other number format.
DATE(Year; Month; Day)
Year is an integer in the range 1583 to 9956 or in the range 0 to 99.
In you can set from which year a two-digit number entry is recognised as 20xx.
Month is an integer in the range 1 to 12 indicating the month.
Day is an integer in the range 1 to 31 indicating the day of the month.
If the values for month and day are out of bounds, they are carried over to the next digit. If you enter =DATE(00;12;31) the result will be 2000-12-31. If, on the other hand, you enter =DATE(00;13;31) the result will be 2001-01-31.
=DATE(00;01;31) yields 31/01/00 if the cell format setting is DD/MM/YY.