In my dataset, dates are stored in text as daymonthyear, where "day" is the date in two digits, "month" is 3-letter abbreviation for the month, and "year" is the 4-digit year. I want to retain month and year in a date or numeric format to ease comparison of data across months. What is the most efficient way to do this?
The most effective approach within the SAS system is to assign DATE and / or DATETIME SAS (numeric) variables. So, then using these numeric variables, you can display them in various formats, while still being able to compare and calculate differences and such with the numeric SAS variable (which are stored internally as days since 1/1/1960 or seconds since 1/1/1960).
I have provided a SAS support website http://support.sas.com/ link to related DOC for your reference (mind any broken URL string):