You can evaluate attendance and absence reasons which accompany time postings using table T555D, Att./Absence Reasons for Subsystem and personnel calculation rules TD80 and TD90.
For further information please refer to concept information Processing attendance/absence reasons in the Time evaluation book.
For information on personnel calculation rules please see RPDSYS00:
CYCL.TD80, CYCL.TD81, CYCL.TD90 (active in schema TM00).
For further information on setting up attendance/absence reasons please see the step Which attendance/absence reasons can be entered at the terminal?.