Until a few weeks ago, the FCC mandated change over date was February 17, but for whatever reason (since it has been publicized for more than a year, the new administration decided to extend the mandated change date to June 12. There is no requirement that prevents the changover however, and in some markets, sevral station changed over starting several months ago when their analog transmitters failed and and the cost to repair could not be recovered.
An interesting observation. It's really easy to tune in an analog TV station. You simply tune to the station and slowly adjust the antenna orientation until you start to see a picture and then keep turning until it's optimized. This method does not work with digital signal TV because you either have a picture or you don't. But all is not lost. Most TVs (and I assume converter boxes) have an autofind menu, and if you look further down the menu you will see a DTV signal strength meter option. Simply manually select the station you want to see, flip the menu to the signal strength meter and turn the antenna to the peak strength. It's really easy that way.
Another hidden gem is
https://www.antennaweb.org
Simply click gtet started and input your zip code (only unless you want to get more spam) and graphically locate your address on the map, and then continue. You will get a listing of all TV stations within range and their compass directions. If you view this graphically and you have an antenna you can manually rotate, you don't even need a compass to point the antenna!
The converter boxes are the cheapest way to go to receive DTV, but they do not receive HDTV which is truly amazing. DTV is basically VGA 640x480 quality which is much better than analog TV. HDTV has even higher resolution, and is labeled as 720 i and p and 1080 i and p, but don't get too worked up on the high priced hype. A $300 HDTV works just as well as a $3000 HDTV, the biggest difference is the screen size and the name on the box, and for practical purposes, there isn't much viewing difference between 720p (which includes 1080i) and 1080p unless you have 20/10 vision.
https://www.dtv.gov/
Bob