Customer has had for a brief moment an accidental time travel on its PI DA server. How to delete the PI values generated in that time slot?

These are realtime tags. Problem is ; when entries were added it was not considered a future entry because the real-time was in the future

Interesting!

I want to ask how these PI tags are defined. Because future values should only be possible to record when the tags are configured for "future data", as opposed to the normal configuration of "Real-time data". Normal tags are unable to record values more than appr. 5 minutes into the future, but future tags can have both future and historical data, so I expect this might be why it was even possible to record these in the future. Are they actively using these tags to record future values?

Ahh, so it's the entire PI Data Archive server that went back to the future.

I would think that reversing the process would work, if you're able to change the computer time to the future again for a moment - and delete the values. If this is not an option, I'd probably ask for techsupport from AVEVA, perhaps they have a way to fix this through scripts or other under-the-hood operations.