A system property controls the time zone that the instance uses for the date and time stamp of a message.

The date and time stamp of a notification uses the system time zone, not the time zone of any recipient. The email property glide.email.append.timezone controls whether to append the time zone. If true, the system time zone of the instance is appended to any Date/Time fields in outbound email messages (for example, 2018-07-02 04:01:14 PST).