I looked through some related recent discussions, interestingly somebody[1] pointed out that this has long been the case in some countries where the military service is mandatory, such as Switzerland (even though the threshold of continuous absence for applying for such a "military vacation" is longer, 1 year in the Swiss case): https://www.armee.ch/de/militaerdienst-urlaub

[1] https://old.reddit.com/r/luftablassen/comments/1s33z9v/wtf_g...