common.Timezone matches UTC and GMT with an optional offset (UTC+2, GMT-05:30, GMT+0530) and a small table of upper case abbreviations (EST, PDT, CET, ...), and sets Context.Location, so "10 pm EST" comes back as 22:00 in a -05:00 zone. A timezone alone does not count as a match. It is not added to common.All, so existing parsers behave as before.