There are 2 main issues relating to ecco's design and the new mellinium.
 
 
1. Recurring dates.
 
Ecco was designed to instantly create a recurring date,  such as 'every tuesday',  or same day every month, etc.
 
however,  a design bug,  causes the auto recurring date to recur only until the current day,  if set after Dec 31 1999.   Ie. will recur only until today = won't recur!
 
 
solution:  manually set the end of each recurring date (custom),  to the desired date. [see photo, select custom and fill in the 'until' date to desired FUTURE date]
alt solution: use the slang extension,  fixes this bug automatically.
alt solution2: use eccomagic XP single click year 2k fix  on a per-item basis.
 
 
2. Bug in reporting changed items to external utilities.   Applies to files CREATED after Dec 31, 1999.
 
You can see/play with this yourself using the FREEWARE EM Developer Tool: DDE/Sync Change Tester tool.
 
Solution: none needed unless you are using external utility which relies on this information report from ecco.
Solution2: none needed unless you are creating 'Raw' new files.  If you use the File > New to create new files,  you are fine.
Solution3: if you create a NEW RAW File (shift or control held down when clicking on File > New),  make sure your FIRST set your clock back to pre Dec 31 1999.
Solution4: Use slang extension, fixes this bug (but not the file.  ie. post 12/31/99 file will still have 'bug' if run on non-slang ecco).