Date Expression	SAS Date Informat	Interpreted As
06Oct59	date7.	06Oct1959
17Mar1783	date9.	17Mar1783

However, if you specify an inappropriate field width, you will receive incorrect results. Notice that the date expression in the table below contains a four-digit year value. The informat does not specify a w value large enough to read the entire value, so the last two digits of the year are truncated.

Date Expression	SAS Date Informat	Interpreted As
17Mar1783	date7.	17Mar1917

Another problem arises if you read a date or time expression using the wrong informat. The SAS log displays an invalid data message, and the variable's values are set to missing.

1---+----10
03/23/98

SAS Log

3 input BirthDate date8.; 4 run; NOTE: Invalid data for BirthDate in line 3 1-8. RULE: ----+----1----+----3----+----4----+----5 3 03/23/98 BirthDate=. _ERROR_=1 _N_=1

When you work with date and time values, check the default value of the YEARCUTOFF= system option and change it if necessary specify the proper informat for reading a date value specify the correct field width so that the entire date value is read.