This chart from Thrill Data shows the average (black line) time a particular boarding group is called at the WDW edition of Rise of the Resistance. The red line is 1/16 and the blue line is so far today (1/17).
As you can see, BG 42 would normally be called between 10-11am. @Shellott_hill has some charts as well that show a little more detail in the Boarding Group Data thread.