I think it’d be better to say “We play at ten in the night.” or “We play in the night at ten.”
I disagree (native British English), the given 'at ten at night' sounds most natural to me.
Don't get when "ko" is required! Seems that it sometimes there and sometimes not.
It's just idiomatic and has to be memorized. Evening and night go with को , while afternoon goes with में . Morning doesn't use a postposition.
For evening ,night,morning,afternoon ko is compulsorily added
Not for morning.
What's wrong in.. We play at 10 pm in the night..?
Very hard to say why (we do say 'in the morning' after all) but it's just not done. It's always 'at' night.
Because '10 pm' already means '10 in the night' (as opposed to '10 am', which means '10 in the morning' so saying both 'pm' and 'in the night' is not needed.
We play at 10 o'clock in the evening was not accepted. I don't see why.
'Evening' would be शाम, whereas रात (as given here) is 'night'.