If you want to know which jobs does not run today (or specific date) because of calendar instructions you could use this command:
select ah_name as Parent_Object,
AJPP_Object as Object,AH_Client as Client, AJPP_Status as Status,(select oh_otype from OH where OH_Name=AJPP_Object and OH_Client=AH_Client) as Type
from ah inner join ajpp on ah_idnr=ajpp_ah_idnr and AJPP_Status=1920 and AH_TimeStamp4 > '20110623'
Please use the correct date for AH_TimeStamp4 (e.g. current date).