The command hmCal_GET OLD TIMERANGE returns the user list instead of the user ID, now. Check your code!
The parameter $9 (user-id) of the callback method is used for the events hmCal_NewAppointment, hmCal_DoubleClickArea, hmCal_ClickArea, hmCal_Drop, hmCal_NewRelation and hmCal_SortUser only. For the other events, use the command hmCal_SET APP USER LIST instead!
The command hmCal_GET OBJECT RECT has new options and returns C_REAL coordinates now. Check your code!
The command hmCal_START ON MONDAY has only effect in the month view. The multi-daily view do not have no more with monday or sunday to begin, but can freely set by the command hmCal_SET START DATE.
Parameters of the command hmCal_DRAG AND DROP PROPERTIES has been changed. Now the command returns a pointer to the source variable.