As I said last time can we please quote these times in GMT. It is hardMark could use GMT when creating maintenance events, and thus cause the reminders to say +00:00, but I wouldn't want to change the reminder feature to always express times in GMT (or UTC+00:00).
To follow international standards the Reminder should say UTC-07:00, so in that sense it is "strange". But writing times with an offset from universal time (whether called GMT or UTC) is a standard usage, and should not be seen as "strange" in the context of any world-wide organization.
Having the Event time and Timezone specified separately is a useful feature for events that happen a physical location. That way the time is expressed in the local time you would be in, were you attending the event. It is the same reason your airplane tickets always specify departure and arrival times in the local time of the respective airport.
I see it is correctly quoted as 4am-5am Saturday in the calendar.Yes the calendar, like the rest of the Groups.io pages (but not including user content), shows you times in your own time zone based on the Time Zone preference in your Account. So I, being in a different time zone than you, see it is correctly quoted as 9:00pm to 10:00pm in the calendar.
By the way, anyone interested in torturing the calendar (or their heads), the U.S. Daylight Savings "fall back" is coming up this Sunday, November 5th. I've put an event in my test group for next Monday, with reminders to be sent tomorrow and Sunday. Those situations bedeviled Yahoo Groups calendars - I'm not sure they ever got it right (I gave up noticing).