"He usually comes home from work around 5:30."
"She goes to bed around 9:30."

Are these sentences grammatically correct?
I always put 'at' before 'around,' like 'at around 5:30.'
Is it okay if we omit 'at' when the preposition 'around' is followed?

Many thanks for your help in advance.

CandyEmotion: smile
It's absolutely correct to omit the "at."
Thanks for answering my question, GG!!Emotion: smile

Actually, this is the question from my son.
I'm not sure whether it's "grammatically" correct or not to omit "at."

Thank you so much for your help Emotion: wink