As the PP said, the online system rolls at 6:00 am ET and the the phone system opens at 7:00 am ET. I personally start with the online system, especially for the hard to get ADRS, because it opens one hour earlier. I prefer the online system because I can search at my own pace and I don't have to wait for the CM to find an ADR, ask about the time, read the fine print about making ADRs, etc. Overall, I've found both systems to work fine, but I prefer the online system.