The current UTC in emails is really really awful for the ‘average user’, especially if you are on the opposite side of the world (i.e. New Zealand).
Many forums using Discourse are rooted in a single Timezone; for those, it would work brilliantly to be able to specify the default timezone displayed in emails for them.
For those that span timezones, yup it is curlier - evidenced by why we still have a 5 year old ‘temporary’ fix. I’d love it if someone considerably cleverer (or at least more dedicated) than me works this out.