Are such words unacceptable? We can't say:
Tell me, what time is it now?
I forgot, how long will your trip last?
Or are the following affimative sentences with indirect questions the only possibility?
Tell me what time it is now.
I forgot how long your trip will last.
As I learnt from the answer and comments, such questions are pretty acceptable in AmE. So the question is if they are also suitable for British English.