Thanks Avi.  That seems to work pretty well and gives me what I was
looking for.  For the time being I am incorporating your change as a
separate class (called MillisecondClockOffset) in my Scheduler package
to avoid changing DateAndTime.  Scheduler is on SM and SqueakSource
for anyone who might be interested in it. Of course, DateAndTime
class>>now still must be overridden as you did, but that was the only
change required to DateAndTime.

So, did you get the sense this change would be never be harvested into
the Chronology classes?  I find it very useful to have millisecond
precision on time now so that things like audit trails can be
accurately generated and replayed plus a host of other reasons.

Regards,

John