I don't know about holidays but Israel uses the same daylight savings as the mentioned Eastern Europe countries, ie switching from UTC+0200 to +0300 at around the same time - only difference is that they start daylight savings on Friday instead of Sunday the same week.

Israelis usually are off on Fridays so it doesn't match the git commit records.

Israelis are usually off from the evening of Friday (sundown) till the evening of Saturday (sundown) for Shabbat. Where did you get the idea that they’re off on Fridays during daytime?

In this context, middle eastern countries with Islam as the majority religion have the day off on Fridays.

in Israel, Friday is generally not a workday (or "business day"), a la Sunday in the western world

I used to work for two Israeli companies and they were always off on Friday and Saturday. They start the week from Sunday.

I don't know all the holidays but they have commits on Yom Kippur dates in 2021 and 2022. For 2023 it's harder to say because their commit activity is sparser.