The Gregorian calendar was created to correct the errors of the Julian calendar, in use at that time. The Gregorian calendar was figured at the starting year of 1582 AD, resulting in its leap year being shifted by 2 years from the solar calendar. In the Gregorian system the leap year is not taken 3 times in 400 years, giving an adjustment every 133.3 years vs. the adjustment in the solar calendar of 128 years.
For clarification read the article: THE JULIAN CALENDAR FOR 30 AD.
Solar leap years are figured, beginning at creation and coming forward, based on the year length of 365.250 days. The actual year length is 365.2422 days, resulting in every four years .0078 of a day in excess of the actual.
On the 128th year there would be 32 leap years. This would result in 8 additional days. The correct number of days is 32 x .2422 equaling 7.7504 days. By not taking a leap year on the 128th year, the calendar is brought back into alignment. Eight days minus .250 of a day not taken, equals 7.750 days, resulting in the actual length of the solar year. This is why there is no leap year every 128 years in the solar calendar.
In 400 years the Gregorian calendar has 97 leap years, resulting in 146,097 days. They should have taken 400 times 365.2422, equaling 146,096.88 days. The difference in 400 years is .12 of a day, making the Gregorian error of 1.68 days from the year of creation.
The math is as follows: 4046 BC years plus 1582 AD years (the year of the change) equals 5628 years. 5628 divided by 400 equals 14.07; times the error of .12 for each 400 years equals 1.68 days. An interesting fact is that this error occurs in the numbering of the months, leaving the replication of the seven day week intact. Therefore, this error does not affect the progression of the seven day week.
Because the Gregorian calendar was figured in 1582 AD, the error of .12 days in 400 years is not significant for the present Gregorian calendar.
God’s hand can plainly be seen here when it is understood that the solar calendar tracks the seven day week beginning at creation and coming forward to the present day. On the other hand, the Gregorian calendar tracks the seven day week from 1582 AD backward and yet they align perfectly for each year.
Don Roth
11-03-23