It seems the U.S. Senate had not planned to be in session on March 4, 1791, but President George Washington summoned them and addressed this message to them:
Gentlemen of the Senate [4 March 1791]
The ‘Act for the admission of the state of Vermont into this union’ having fixed on this, as the day of it’s admission, it was thought that this would also be the first day on which any officer of the Union might legally perform any act of authority relating to that state. I therefore required your attendance to recieve nominations of the several officers necessary to put the federal government into motion in that state.
For this purpose I nominate &c. [Nathaniel Chipman to be judge of the district of Vermont; Stephen Jacobs [Jacob] to be attorney for the United States in the district of Vermont; Lewis R. Morris to be marshal of the district of Vermont, and Stephen Keyes to be collector of the port of Allburgh, in the State of Vermont.]
(The word it's and the word recieve are spelled in those ways on the linked web page.)
Note that he wrote "it was thought", without saying who it was who thought that. But nine days earlier the secretary of state, Thomas Jefferson, wrote this:
The Secretary of State having recieved from the Commissioners for the State of Vermont a letter proposing these Questions 1. Whether, as that state will not be a distinct member of the union till the 4th. day of March next, the President can, before that day, nominate officers for it? and 2. if he cannot, whether he can nominate them after the recess of the Senate? makes thereon to the President of the U. S. the following Report.
He is of opinion the President cannot, before the 4th. of March, make nominations which will be good in law: because, till that day, it will not be a separate and integral member of the U. S. and it is only to integral members of the union that his right of nomination is given by the Constitution.
But that nomination may be made on the 4th. of March, and, if the Senate will meet on that day, may be reported to them for their approbation. [ . . . ] This therefore is what the Secretary of State thinks best to be done.
Th: Jefferson Feb. 19. 1791.
My question is whether that precedent has stood.