Hello münsterorganist,
I don't know how PACE's software works internally with regard to timestamps, but in general it's very important that your computer's clock is (at least approximately) correct, and that the clock's battery isn't dead. Lots of software (including Windows itself, drivers, installers, etc.) have dependencies based on timestamp comparisons (e.g. determining whether to install or update individual files, depending on whether corresponding existing files' timestamps are newer or older). If the computer's clock becomes significantly wrong (e.g. reverts to an earlier point in time), then you may well get all manner of problems and strange behaviour with the computer, and potentially even need to re-install everything from clean (re-format the drive, etc.) in an extreme case.