Then take it up with Paramount and Roddenberry. TMP pretty firmly places TOS in the 23rd century. Unless Voyager VI launched before the 1900's.
Before TNG came along and I became convinced that Earth events were dated in different Earth calendars in different episodes, I believed - like most
Star Trek fans still believe - that all dates are given in one calendar, the Gregorian calendar. Thus I believed that the historical date in "Wolf in the Fold":
2156. Heliopolis, Alpha Eridani Two. Ten women knifed to death.
Was the most recent historical date before TOS.
And the dialog in "Where No Man Has Gone Before" seemed important:
MITCHELL: My love has wings. Slender, feathered things with grace in upswept curve and tapered tip. The Nightingale Woman, written by Phineas Tarbolde on the Canopius planet back in 1996. It's funny you picked that one, Doctor.
DEHNER: Why?
MITCHELL: That's one of the most passionate love sonnets of the past couple of centuries. How do you feel, Doctor?
If something written during "the past couple of centuries" was written in 1996, the date of "Where No Man Has Gone Before" would have to be in the period 2096 to 2196. Since the five year mission could last about five years if the name was correct, the very latest TOS and TAS episodes could happen as late as 2101 to 2201.
So combining those two sets of data gives a possible date range of 2156 to 2201 for TOS and TAS. That is the period where I set my early
Star Trek chronology, and that is the only possible date range for TOS and TAS for people who still think that all dates are given in the Gregorian calendar.
According to "Where No Man Has Gone Before" the
Valiant was lost over two hundred years earlier, and thus in or before the period of 1956 to 1996 that would be exactly 200 years before "Where No Man Has Gone Before". So Earth had warp drive or some other form of faster than light travel by the period of 1956 to 1996.
But "Space Seed" shows that Earth doesn't have faster than light travel in the 1990s:
MARLA: Captain, it's a sleeper ship.
KIRK: Suspended animation.
MARLA: I've seen old photographs of this. Necessary because of the time involved in space travel until about the year 2018. It took years just to travel from one planet to another.
Therefore, Earth had a form of FTL interstellar travel before the 1990s, but didn't during the 1990s, and discovered the same or a different form of FTL interstellar travel in about the year 2018, or possibly much later than 2018.
Thus in TOS, as in James Blish's
Cities in Flight, Earth discovers FTL interstellar travel and begins exploring and colonizing other stars independently twice. It is possible that aliens or time travelers gave the knowledge of FTL space travel to a group of Earth people who kept it secret from the rest of humanity and eventually left Earth and never returned until after being contacted by the second group of explorers from Earth. So the first secret group could have sent out a series of voyager probes before 1900 and left Earth before the 1990s.
And that is the type of chronology you get if you assume that all dates are given in the Gregorian calendar.