iCal and Google calendar are talented - they can detect events from your texts, emails, and facebook and add them to your calendar. However, this technology is not always accurate. 

Below is an example from Google Calendar. On occasion, Google sends email invitations with the wrong appointment times. Sometimes it will be the correct time but in the wrong time zone.

These emails are not from 'Aiea Pearl City Dental Care. As referenced in the email it is an "Invitation from Google Calendar" and to sign up for a Google account to control your notification settings. Please disregard these emails, check your phone's settings and time zone, or check iCal and Google calendar settings. Our emails should always have our logo on it. 

We are sorry for the confusion, thank you for your understanding.