mswiz777, this was the only relationship I could find between 566 (straight) and the 466 combo:
10/31/2016,566,020
11/01/2016,734,606
11/02/2016,968,227
11/03/2016,270,792
11/04/2016,550,947
11/05/2016,021,507
11/06/2016,729,750
11/07/2016,362,803
11/08/2016,722,797
11/09/2016,834,323
11/10/2016,081,234
11/11/2016,722,809
11/12/2016,086,056
11/13/2016,084,693
11/14/2016,350,323
11/15/2016,576,566
11/16/2016,176,382
11/17/2016,343,549
11/18/2016,266,811
11/19/2016,857,763
11/20/2016,913,262
11/21/2016,408,765
11/22/2016,693,646
I'll tell you a little secret. I thought for sure we were going to get 466 back in February. When we didn't, I had a flash that it wouldn't fall until September. That seemed like a long way off, so I didn't post about it. Now, September is two weeks away and I'm thinking very hard about that little chart I just posted above. Just for fun, I extended that chart into September to see how things might line up. Here it is:
Now | 2016 when 646 last fell
08/16/2019,566,??? | 10/31/2016,566,020
08/17/2019,???,??? | 11/01/2016,734,606
08/18/2019,???,??? | 11/02/2016,968,227
08/19/2019,???,??? | 11/03/2016,270,792
08/20/2019,???,??? | 11/04/2016,550,947
08/21/2019,???,??? | 11/05/2016,021,507
08/22/2019,???,??? | 11/06/2016,729,750
08/23/2019,???,??? | 11/07/2016,362,803
08/24/2019,???,??? | 11/08/2016,722,797
08/25/2019,???,??? | 11/09/2016,834,323
08/26/2019,???,??? | 11/10/2016,081,234
08/27/2019,???,??? | 11/11/2016,722,809
08/28/2019,???,??? | 11/12/2016,086,056
08/29/2019,???,??? | 11/13/2016,084,693
08/30/2019,???,??? | 11/14/2016,350,323
08/31/2019,???,??? | 11/15/2016,576,566
09/01/2019,???,??? | 11/16/2016,176,382
09/02/2019,???,??? | 11/17/2016,343,549
09/03/2019,???,??? | 11/18/2016,266,811
09/04/2019,???,??? | 11/19/2016,857,763
09/05/2019,???,??? | 11/20/2016,913,262
09/06/2019,???,??? | 11/21/2016,408,765
09/07/2019,???,??? | 11/22/2016,693,646
It may not be correct, but it does give an expected date in September for a 466 combo number.
P.S. Here are the Date workup hits for 466 combo numbers in September:
09/04/2007,683,646
09/06/1995,009,466
09/11/1991,XXX,646
09/26/1995,844,466
09/29/2016,600,466