The "immediate cause" is that this looks  like the conceal flag is set. I
don't know how this made it into the entry. We found a serious bug in the
IBM C compiler  and for half a  day American ran with  the buggy version.
The bug caused LISTSERV to think that all events on earth occurred on Oct
28, 1900. That is, a central date conversion routine always returned this
result when compiled with optimization. We immediately recompiled without
optimization  and sent  American a  fix. Other  routines might  have been
affected. IBM sent us a fix which  did not solve anything and we're still
talking to them. We're probably going to  switch to gcc if they don't fix
this problerm soon.
 
  Eric