Wait, I think I understand now.  In the second query, >8:01 is what I actually want since it was currently 9:01.  FirstDate is stored in UTC but my client is automatically adjusting, so it works when I compare it to UTC.  The local value for "OnlyAfterThisDate" isn't adjusted when displayed.

I'm not sure I'm verbalizing it correctly, but I think I do understand now.

This might better explain what I'm seeing or not understanding:

SELECT DATEADD(hh, -1, GETDATE()) as OnlyAfterThisDate, MIN(TimeCreated) as FirstDate, MAX(TimeCreated) as LastDate FROM ens.messageheader WHERE TimeCreated > DATEADD(hh, -1, GETDATE());

SELECT DATEADD(hh, -1, GETUTCDATE()) as OnlyAfterThisDate, MIN(TimeCreated) as FirstDate, MAX(TimeCreated) as LastDate FROM ens.messageheader WHERE TimeCreated > DATEADD(hh, -1, GETUTCDATE());