why does pub.date:getCurrentDateString give different result

I get different results when I invoke pub.date:getCurrentDateString from within a flow service, as opposed to invoking it from IS Administrator.

I invoke the pub.date:getCurrentDateString service with the following input:
pattern: HH:mm

Assuming the computer clock reads 12:34 (about noon, daylight savings time in Wash D.C.)

When invoked from a flow service I get this result:
12:34 (which is expected, local daylight time)

When invoked from IS Admin I get this result:
16:34 (which happens to be GMT, not local time)

When I provide a timezone=EST, both return 11:34 (GMT-5), which is the correct EST, but I want EDT (GMT-4) (however, there is no such official timezone)

BTW, I am running IS 6.5 SP1 on Windows
The behavior is the same with either the SUN or IBM jre
JAVA_DIR=C:\webMethods6\jvm\win142\jre ( java 1.4.2_07 with SUN’s daylight saving patch applied)
JAVA_DIR=C:\WebSphere60\AppServer\java (java 1.4.2 with IBM’s daylight saving patch applied)

Were you able to resolve this issue. We are facing the same with 6.5 SP 2 and 1.5 jvm.