Not familiar with Kernel maintainers but do some never take full 2-week long holidays??
If in US, that'd be once in a lifetime - e.g. for your honey (half) moon.
And then we have Easter, Pentecost, ascension day, Christmas, New Year’s Day. All public days off.
Personally for a long time my contract was 36 hours, get you 1 more day off every 2 weeks.
That American system sounds so depressing, but I guess you get used to anything.