Past Calendar Changes
The calendar now in use, a Roman calendar, has been changed, but that change did not break the weekly cycle.
Prior to its change, it was called the Julian calendar, because it originated at the time of Julius Caesar, 45 B.C. -- several years before the birth of Christ. The one change was ordered by Pope Gregory, and since then it has been called the Gregorian calendar.
The Julian Calendar was imperfect -- it inserted leap years too frequently. Back in 45 B.C. they supposed the year was exactly 365 1/4 days long, and to take care of the extra one-fourth day each year, added a day to the month of February every four years. But it was found later the year was 12 minutes and 14 seconds shorter than this. Consequently, by the time of Pope Gregory, the calendar had drifted TEN DAYS away from the seasons. The Spring equinox, consequently, fell on March 11th, instead of March 21st.
To correct this, ten days were dropped from the calendar. But they were dropped only from the number of days in the MONTH not from the number of days in the WEEK. A man named Lilius proposed the method which was adopted in making the change. In the Catholic Encyclopedia, Vol. 9, p. 251, under article "Lilius," explaining this change, we read:
"Thus, every imaginable proposition was made, only one idea was never mentioned, viz., the abandonment of the seven-day week."
In the Catholic Encyclopedia, Vol. 3, p. 740, article "Chronology," we read:
"It is to be noted that in the Christian period, the order of days in the week has never been interrupted. Thus, when Gregory XIII reformed the calendar in 1582, Thursday, 4 October was followed by Friday, 15 October. So in England, in 1752, Wednesday, 2 September, was followed by Thursday, 14 September."
Since the Catholics changed the calendar, the Catholic Encyclopedia is the best historical authority there is on the question, and is proof positive.
So that the reader may clearly understand it, and SEE how it was worked out on the Calendar, we reproduce below the actual calendar. The change was made in Spain, Portugal, and Italy, in 1582.