Hehe. 12 hours!
In India it’s routine (in fact standard) for US companies to have the Indian on-call person for 24x7 on-call. Rarely companies have follow the sun policy. Very few! Definitely not Ubers and Amazons.
And Indian managers are the enforcers of this - it’s probably one of the only significant USP these managers have “I’ll get it done by same engineers at the lower Indian rates“.
US HR and leadership wash their hands off the problem - “oh, we give you full ownership, you should decide and own this” :)