I have had limited success with the following format:
Subject: My test event
Email body says:
This is my test event!
When: May 7, 9-10AM
Where: 123 Main Street, Berkeley, CA
Using the keyword "Location" instead of "Where" seems to work also.
In Google Calendar, this will populate the Subject, the body and the event time and the event location (The field labeled "Where").
I have been using the above format with my personal Gmail account, and my institution's Google Apps account. It usually works with the "Add to Calendar" button, and with the "More: Create event" menu option.
That's an unusual calendar strategy.
Reminders work by sending an alert (email, popup, SMS) at X minutes/hours/days/weeks before the start time of the event.
You can set multiple reminders for an event, so you could do something like have a reminder sent three hours prior, then two hours prior, then an hour, then fifteen minutes. (If that's something you want to do.)
So, for your 12:00 appointment, you would create the actual event at 12:00. To receive a reminder at the time the event starts, create a reminder for 0 minutes "before" the event. If you want a reminder sent at 7:00, just create a reminder for 5 hours before the event.
Having a reminder sent after the event is to have taken place would seem to make no sense and it's no wonder to me that that's not how it's implemented. (For what it's worth, I've never seen any other calendar app implement reminders after the fact.)
Perhaps if you edit your question to explain why you're trying to do what you're doing, we might be able to offer a more viable strategy.
Best Answer
Go to calendar.google.com, hover over the calendar that you got that notification from in the side bar, click the down arrow, and then select "Edit Notifications". You can then select/deselect the notifications you wish to be e-mailed for. "Canceled Event" seems to be the notification that you received.
Alternately, you can go to
Settings > Calendarsto see the links to each calendar's notification settings.