For non-SMS-managed data sets, the processing depends on whether the DAYS parameter is specified on the MIGRATE command.
If the DAYS parameter is not specified on the MIGRATE command, DFSMShsm checks the time since the data set was last opened against the value of the MIGRATIONLEVEL1DAYS parameter of the SETSYS command. If the data set has not been opened for a number of days more than or equal to the value specified by MIGRATIONLEVEL1DAYS, the data set migrates to ML2.
If the DAYS parameter is specified on the MIGRATE command, DFSMShsm checks the time since the data set was last opened against the value specified with the DAYS parameter. If the data set has not been opened for a number of days more than or equal to the value specified by the DAYS parameter, the data set migrates to ML2.