Why are these PF dates inconsistent?

[renormalize]

I was looking at this recently revived thread: https://www.physicsforums.com/threads/a-homebrew-quantum-computer-simulator.1013770/ and noticed the following regarding a posting by @azntoon on March 30, 2022:

How can the Last-seen date be 10 years before the post date?

 

[Tom.G]

How can the Last-seen date be 10 years before the post date?

TIME TRAVEL!
Now if we can just bottle and sell it ....

 

[Borek]

Apart from the obvious answer (bug) there is always possibility system updates some information during maintenance events, say once a day, so different parts of the database can be temporarily off.

But in general these old things were imported from the previous version of the forum database at some point and in my experience they do contain some strange inconsistencies.

 

[DrGreg]

How can the Last-seen date be 10 years before the post date?

Maybe the user changed their privacy settings in 2012?