Yes, time zone was the problem …
but, in the future, how do I insure that Time is always displayed “as entered” , regardless of locale?
for info only:
on servoy server, our default locale is “US”
all macs are set to US, New York
but, the time zone on the Citrix Presentation Server 4.5 was set 4 hours off
so Mac users displayed the “wrong” time.
Windows users displayed Time properly, perhaps by grabbing the client’s time zone (see below)
it appears that Citrix Server can grab the Citrix Client’s time zone http://support.citrix.com/article/CTX303498
now I need to find out why our Macs do not properly report “New York”