File delivery timestamp

Is the file timestamp driven by the site FTP settings? The attached file contains an example. I'm in ET, and assume this indicates the files were sent 8:31am ET. Someone in PT should still see 8:30am ET timestamp, versus 5:30a PT, correct?

In general that's correct.

Though with some FTP servers (like IIS) that do not provide the timestamp in UTC/GMT, some additional configuration might be needed to achieve this.