From the second Sunday in March to the first Sunday in November, we are in Daylight Saving Time, which is denoted as follows:
EDT/CDT/MDT/PDT
For the rest of the year (Nov-Mar), we are in Standard Time, denoted as:
EST/CST/MST/PST
If you have been telling your guild that you plan to begin raiding in October with a start time of 8:00 PM EST, than that’s wrong. Use EDT instead.
Alternatively, to ensure you’re always correct and never have to make seasonal updates, just use the following, which essentially means “whatever time my clock currently says”:
ET/CT/MT/PT
Note: If you are in Arizona, or any other area that doesn’t observe Daylight Saving Time, then you will always use Standard Time.