In the article 14814 we described a way to configure to format the dates in a notification that could work in Quick Actions, Workflows or Business Rules showing the same result including the TimeZone. However, this was a probably too complex and we needed to modify the daylight function two times a year.
Since HEAT SM 2015.1 there is a simpler option.
Since HEAT SM 2015.1, the FormatDate function allows to specify the timezone.
$(FormatDate(CreatedDateTime, "dd/MM/yyyy hh:mm tt", "America/Panama"))
If CreatedDateTime is 15/7/2015 4:01 PM (UTC), the above expression will always result in "15/7/2015 11:01 AM" (UTC-5), whatever context it is run in.
If we don't specify a TimeZone, the expression evaluator uses the client-context TimeZone. For workflows there is no client-context, so UTC is assumed.
Therefore, specifying the TimeZone in all the cases should solve the problem.