ZDT is the Z-System Day Timer, a daily planning calendar derived from 
ZDB.  If your system has a real-time clock, ZDT automatically reads it 
and displays the current day's schedule, checking the data file for any 
previously entered appointments, memos, etc.  ZDT will also work with 
manual date entry.  Requires ZCPR 3.0 or higher, VLIB4+ and extended 
TCAP.  Small, feature packed just like ZDB.  Joe Mortensen, 08/04/91