Possible bugs should be posted over in Report an Issue.
This is a known bug, Seems that FileMaker can't figure out that Daylight Savings Time is in effect.
For More Information see: FMServer Email Notifications have incorrect sent time
This is one of many acknowledged bugs that can be found in the Known Bug List thread here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: https://www.dropbox.com/s/jt09b82i0xijbu3/FMP%20Bugs.zip
Hey Phil, thanks for the links. I obviously didn't do enough research.