Final answer:
The answer to the question regarding when the first Sgt.Maj. was appointed does not match any of the choices provided. The first Sergeant Major of the Army was established on July 11, 1966, which is not listed among the options.
Step-by-step explanation:
The question First Sgt.Maj. was appointed on what day? does not correspond to any of the provided dates. The positional title of Sergeant Major often varies between military institutions and their historical timelines, so without more context, it is difficult to provide a precise answer. None of the dates listed, such as January 1, 1801, April 1, 1977, August 16, 1979, or February 16, 2023, or the additional reference dates provided from the span of 1787 to 1937, give any relevant information concerning the appointment of the first Sergeant Major. Furthermore, the first Sergeant Major of the Army, a specific high-ranking non-commissioned officer in the United States Army, was established later than any of these dates, on July 11, 1966, with SMA William O. Wooldridge being the first to hold that position. Therefore, the correct answer to this question is not available from the choices or reference dates given.