correct usage

It is unnecessary:

– Once the restaurants and shops on the ground floor close for business each night at 10.30, Bugis Point in North Bridge Road goes quiet.

You would use p.m. this way, with a space:

– Once the restaurants and shops on the ground floor close for business each day at 10.30 p.m., Bugis Point in North Bridge Road goes quiet.

Thanks, hightor, for taking the time and effort to answer my question clearly and in great detail.