public ThemeType geCurrentThemeType() {
        return Theme.getThemeType(currentPreferences.getTheme());
    }
An offset specifies the hours, and optionally minutes and seconds, difference from UTC.
It has the format hh[:mm[:ss]] optionally with a leading sign (+ or -).
The positive sign is used for zones west of Greenwich.
(Note that this is the opposite of the ISO-8601 sign convention which is output on format.)
hh can have one or two digits; mm and ss (if used) must have two.

@param userTimeZone The user time zone to get the POSIX compliant offset string for.
@return The POSIX compliant timezone offset string.
stroom-core-client/src/main/java/stroom/preferences/client/UserPreferencesManager.java