Google is unhappy with arabic calendar dates we currently have showing up in <time> tags:
https://ar.wikipedia.org/wiki/%D8%A8%D8%B7%D9%88%D9%84%D8%A9_%D8%A7%D9%84%D8%B9%D8%A7%D9%84%D9%85_%D9%84%D9%83%D8%B1%D8%A9_%D8%A7%D9%84%D9%82%D8%AF%D9%85_%D8%AF%D8%A7%D8%AE%D9%84_%D8%A7%D9%84%D8%B5%D8%A7%D9%84%D8%A7%D8%AA_2008
```
<time itemprop="startDate" datetime="2551-09-30T20:30:00+00:00" style="display:block;overflow:auto"><span class="mobile-float-reset" style="display:block;float:left">30-09-2551</span><span class="mobile-float-reset" style="display:block;clear:left;float:left">20:30</span></time>
```
The errors started on December 26:
{F31502205}
I presume Google expects Gregorian dates instead in those HTML tags.
I'm speculating that this might have to do with Parsoid-PHP since it seems to be a new issue, but it might be unrelated and an older problem.
I don't know if it's actually fixable, or need to be fixed.