WWII U.S. Navy report, "Date of Precedence" question

I'm researching a friend's Dad who served in the Navy during WWII. In reading a period summary report of officers the report has a column with the title; Date of Precedence. Doing further reading I think I understand the field title to mean the date to which a person is entitled to that pay grade. Anyone know for sure?

In this case I am trying to isolate his enlistment date, which has not been easy and I think this date represents when he was given his Ensign rank. I have located several muster reports after this date that show him serving on various ships. I've attached the report heading and part of a sample page. Thanks in advance.

 

Yes, the "date of precedence" shown in your shots of the 31 July 1944 USNR Register is his date of rank.

For aviators (the AVN, AVG, AVT types), some people mistake this date as also being the date one was designated a naval aviator, but that is not true; commissioned naval aviators were commissioned first and then designated naval aviators anywhere from 1 to 10 days later, sometimes even longer.

 

And, if you can find a muster roll on which your subject appears as an enlisted man, presuming the yeomen were doing their jobs, the place and date of his last enlistment should appear on the right hand side. Obviously, the older the muster roll you can find the closer you get to his actual enlistment date and place.