SAS | Date Formats and Informats

Informats is used to tell SAS how to read a variable whereas Formats is used to tell SAS how to display or write values of a variable. Informats is basically used when you read in sample data which is being created using CARDS/DATALINES statement or read or import data from either an external file (Text/Excel/CSV). Formats can be used in both Data Steps and PROC Steps whereas Informat can be used only in Data Steps. Example: Read Dates in SAS

• In the example below, we have used INFORMATS ddmmyy8. and ddymmyy10. to read dates in SAS. It creates a dataset called sampledata which is stored in WORK library. SQL

  DATA sampledata;
      INPUT @6 date1 ddmmyy8. @15 date2 ddmmyy10.;
      CARDS;20-07-19 20-07-2019 ;
  RUN;
  

  The INFORMATS ddmmyy8. is used to read 20-07-19 date and ddmmyy10. to read 20-07-2019 date. In defined syntax above, 8 and 10 refers to width of the date. The created dataset looks like below - It returns 21750 as it is in the SAS date value form. It is not meaningful if you look at the value. You cannot tell which date it is.
• To display the date in usual date format, use FORMAT statement. SQL

  DATA sampledata;
      INPUT @6 date1 ddmmyy8. @15 date2 ddmmyy10.;
      FORMAT date1 ddmmyy8. date2 ddmmyy10.;
      CARDS;20-07-19 20-07-2019 ;
  RUN;
  

  Output:
• How to read DD-MMM-YY format You can use date11. format for both DD-MMM-YY and DD-MMM-YYYY format. SQL

  DATA temp;
      INPUT @6 dt date11.;
      FORMAT dt date11.;
      CARDS;20-jul-19 ;
      PROC PRINT noobs;
  RUN;
  

  Output: