The object returned by now() doesn't have a timezone. It is UTC with millisecond precision wherever it is. It is shown relative to a timezone only where it is converted to a string. Convert it to a string in the gateway, you get the gateway timezone. So too with designers and Vision clients.
Perspective scripts and bindings run in the gateway, so you get gateway time. If you allow a date/time object to travel to the browser, it will get the underlying UTC milliseconds, and many Perspective components will understand and apply the browser time zone. If you need more control, you will need to use time-zone-aware string conversions in your gateway. See this topic and the linked topic within: