IBOC is not authorized currently for night use. It is ok to turn it on
at sunrise and have it run til sunset, I believe. Sunrise and sunset
are the two prime DX times on MW.

The broadcasters want it at night I think - which mean the FCC will
allow it eventually. They have to pretend to go through an
evaluation/consideration period first.

I can't see it succeeding on MW. Perhaps FM. I hope it does die a
quick death on MW.