Dates in Ignition are objects containing UTC milliseconds, no matter the time zone. When you ask for an object to be assigned to a text property, Java will stringify it right there, which is in the gateway for expressions. Java default stringification of dates uses the JVM timezone, which is UTC in your case.
The designer is a separate JVM, and it will stringify locally for you. Perspective browsers will not, unless you trigger native timezone handling (not available in a label).
See this topic for options: