You can control the expiration date of data sets based on their last reference date.

• With the EXPDT retention method, the expiration date can be set based on the last usage. DFSMSrmm uses the data set LASTREF extra days to evaluate the data set expiration date. The extra days are added to the date of last reference. The data set expiration date is set to the maximum of the dates calculated by using data set LASTREF extra days and the current expiration date. Any reference to the data set by a write or read operation will redetermine the expiration date. When a new tape data set is created the LASTREF extra days attribute can be set from:
  • The parmlib OPTION RETENTIONMETHOD(EXPDT(LASTREF(extra_days)))
  • The management class expiration attribute ‘Expire after Days-Non-Usage’, if the use is enabled by DFSMSrmm MCATTR parmlib option and if the data set is associated with such a management class. For information on how the exploitation of management class expiration attributes can be enabled in DFSMSrmm see “Using the parmlib member EDGRMMxx” in z/OS DFSMSrmm Implementation and Customization Guide. For information on exploiting the management class attributes for tape, see “Exploiting Management Class attributes” z/OS DFSMSrmm Implementation and Customization Guide
  • TSO command ADDDATASET / CHANGEDATASET LASTREF(extra_days)
• With the VRSEL retention method, you can specify the LASTREFERENCEDAYS operand when adding a data set or name vital record specification for data sets to be retained based on last usage. For more information, see ADDVRS: Adding a vital record specification.