What I learned this morning: It is not even a matter of range or not. But they seem to prefer Friday nights. Is this some weird idea of CME/Globex ONLY or do you know of other (electronic) exchanges that cancel GTC orders ?
I got a notice this past Friday telling me that Globex was cancelling all GTC orders after close as they were restructuring their computer system. I'm not so sure it's every Friday as you suggest.
Don't know of any other exchanges that do it. Perhaps try asking the Globex rep on the IB discussion board why they do it.
stop limit orders are NATIVE stop market are held on the IB servers. time doesn't matter. You can configure your stop triggers via the the configure tab of the TWS.