Why would moving the prime meridian hasten the time when it would be necessary to drop a day from the calendar? I'm reading the sci-fi novel Saint Leibowitz and the Wild Horse Woman, and in the story a pope in the post-apocalyptic future moves the prime meridian from England to the U.S. It is an unpopular decision, because according to the author not only would it confuse navigation, but it would decrease the amount of time until it is necessary to drop a day to keep in line with planetary movement. I'm trying to understand the logic of this, but I don't get at all why this would happen.
There is no basis in logic to have to subtract a day due to a change in the prime meridian.

Both the Julian &amp; Gregorian calendars require days to be added, not subtracted. It's why we have leap years.

Also, both the Julian &amp; Gregorian calendars were established centuries before the prime meridian was set in the 19th century. The formula for adding days &amp; creating leap years was set long before the prime meridian was even contemplated.