Oh I remember this also for setting older dates in VMs. In the end, it was a cat-and-mouse game as of course the authors of these softwares could easily detect such "temporal inconsistencies".
> ... as of course the authors of these softwares could easily detect such "temporal inconsistencies"
Not easily at all. It was near impossible.
Without access to the Internet it was always impossible for, say, a software from 1999 from being able to tell it was ran in, say, 2005. I had shitloads of "Ghost" (before it became "Norton Ghost") images, ready, with a Windows installation at a specific date. I'd re-image an entire HDD (it was very fast back then when images were small and HDD even smaller, even if they were slow by today's standard) and set the clock of the PC. There was simply no way for a software to then detect we were in 2005 and not 1999.
Without Internet and without any file dated "in the future", there was simply no way to detect any inconsistency.
Back then users where in total control of the hardware and of the PC's clock. There was no way around it.
EDIT: I'm not talking about VMs btw, but running on bare metal, just set, in an undetectable way, at a date in the past.
You are right. I just thinked of a pirated version of Adobe Photoshop I once run for years just by keeping the system time basically constant, without changing anything else. Inconsistencies in this "scheme" are easy to check, just create a few "cornermark" files with timestamps. At startup, scan for these files and check if their timestamps are in the past. Of course this can be easy to "hack" from a user perspective, which is why I told this a cat-and-mouse game :-)
https://joeldare.com/that-time-i-built-a-crack-for-nearly-al...