I encountered the idea of the 'night watch' and in fact the three traditional military watches of the night and their relationship with historical sleep patterns around the world thanks to The Paleolithic Prescription (1988) by Boyd Eaton, et al.[1]. Beyond introducing the idea of a paleolithic diet, Dr. Eaton along with his colleagues and students researched sleep and activity patterns in historical texts (records of Victorian doctors), the anthropological record, and practices of contemporary indigenous groups. As I recall, they found three sleep patterns commonly coexisting through recorded history and around the globe.

1) The night owl's late to bed and late to rise (first military watch)

2) The Dagwood Bumstead early to bed, up in the middle of the night, late to rise (second military watch)

3) Poor Richard's "Early to bed and early to rise" (third watch)

It was theorized that the three military watches possibly arose from prehistoric humans in small bands gaining survival advantages from having subsets of group members awake throughout the night.

I should also mention that long standing human practices involving nights when groups went without sleep showed up around the globe were studied as well. These existed independent of and seemingly well before showing up in academic settings and post industrial workplaces.

[1] https://www.kirkusreviews.com/book-reviews/a/brothers-grimm-...

Yes, all-nighter neighbourhood parties centred around prayer and group singing of religious music have been an integral part of Hindu religious practice for a long time. They are literally called “jaagran” (‘keeping awake’) or “jagraataa” (‘night-wake’).

Wouldn't you know it, when Christians do the same thing, it's called a vigil, from the Latin for.. being awake!

https://en.wikipedia.org/wiki/Vigil_(liturgy)

I wonder if jaagra- and vig- come from the same root? Wouldn't that be fun.

I'm thinking of the derived word "vigor" which means strength and energy, apparently the PIE root is *weg- from which we also get "awake".

So this is very likely a cognate!

Edit: the related word, turns out, is excited, not vigil.

That would have been fun! But in this case it doesn't work. The PIE root is *h₁ger-

https://en.wiktionary.org/wiki/%E0%A4%9C%E0%A4%BE%E0%A4%97%E...

Except this appears to be a mistake! (Read on, it isn't)

If we follow the Sanskrt we get the cognate jaagarti: https://en.wiktionary.org/wiki/जागर्ति#Sanskrit

Which lists the root as *h₁ger- (“to be awake, to awaken”).

But that root is missing from Wiktionary, which isn't a good sign, but compare:

https://en.wiktionary.org/wiki/Reconstruction:Proto-Indo-Eur...

Although tracing this forward I see the obvious derivatives (vajra, vaaja) and it would be peculiar, but not unheard of, for the word to take two mutations.

I'm basically on a random walk at this point, but here's that missing root again https://en.wiktionary.org/wiki/ἐγείρω#Ancient_Greek and I am once again left wondering...

Exitare! Ok. Nope completely different roots. Someone should really write up *h₁ger- it's pretty important...