As one example, some clocks are cpu specific (rather than system specific). When a thread gets scheduled to a different cpu, it might be talking to a different clock, and getting a backwards time.
The user might also be changing the clock while the program is running, of course.
If the forward direction of time is important, make sure the the source of time is a monotonic clock API.
E.g., this blog is in Hebrew, you can see the expected text layout on its website: https://workaround.blog/
I wonder if Newsboat can replicate that layout. Here is the RSS feed:
https://workaround.blog/feed/