You are right, wanting to go backwards is problematic.
I agree that slowing down the system time is the way to go (not smitty now). The other option did occur to me too, but it's slightly more risky as I don't know 100% what else I might effect and getting downtime for all the databases may be an issue.
I will find out what we are doing about a time-server for these production servers.
Thank you for all your advice.
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Edit: made the change yesterday,
AIX date command
Aix, changed the date to lose 7080 seconds,
date -a -7080.0
all working ok.