Gregorian Calendar/Mistake

Source Work

 * The Dictionary
 * $3333$
 * $3333$

Mistake

 * The Gregorian calendar is approximately $1$ day ahead every $3333$ years.

Correction
Using a value of $365 \cdotp 2422$ days per tropical year, it can be established that the Gregorian calendar starts one day later relative to the tropical year after $3333$ years (to the nearest day).

Using the more precise value of $365 \cdotp 24219 \, 878$ days in the tropical year, it is shown in Discrepancy between Gregorian Year and Tropical Year that the number of Gregorian years after which there is a day's discrepancy is in fact $3319$ (to the nearest day).

In of $1997$,  uses the more precise $365 \cdotp 24219 \, 878$, to obtain an approximate value of $3320$ such years.

The section $3333$ has been dropped from of $1997$.