Altered calendar theory

Is this the biggest conspiracy in history?

This is the ghost time hypothesis, which claims that we are actually in the year 1722!
The idea is that three men, Otto III, Silvester II and Constantine VII, agreed to change the time and set the years 614-911 A.D. so that they could live in the year 1000 A.D.
The main evidence for this is that there were discrepancies between the Julian and Gregorian calendars, leading to the conclusion that three centuries never really existed, and due to a lack of historical evidence, the three centuries were recorded in the Carolingian calendar.