February
2 of the 6 encyclopedias on this shelf carry an entry for February. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
the second month of the year. In the old Roman calendar it was the last month of the year. The name is derived from a Roman word, meaning to purify, February being the season of the year when people were held to purify themselves prior to the approaching religious festivities. It is allowed but twenty-eight days, with an additional day in leap year , or the year the number of which is divisible by four; save that, in the year completing a century, a day is not added unless the year be divisible by four hundred. The shortness of the month is due to the fact that two days were stolen from it to lengthen the months of July and August, named in honor of the Roman emperors, Julius and Augustus. Several days of February are especially noted. The second is Candlemas Day, one of the quarter days in which rents are due in Scotland; the fourteenth is St. Valentine's Day. Locally in the United States , the second of February is called Groundhog or Woodchuck Day. The saying goes that on this day the woodchuck comes up and looks about him. If he can see his shadow, that is, if the day is bright and clear, he goes back to his burrow for six weeks. At the end of this period, spring may be expected.
Collier's New Encyclopedia (1921)
the name of the second month of the year. It contains in ordinary years, 28 days, and in bissextilis, or leap year, 29. By the calendar of Julius Cæsar, February had 29 days except in bissextile, or leap year, when it had 30. But Augustus took a day from it, and added it to his own month, August, that it might not have a less number of days than July, dedicated to Julius Cæsar. Previously August had been called Sextilis, and consisted of 30 days only.
What Has Changed in the Last Century
The arithmetic both accounts give still governs the calendar exactly: February has 28 days, 29 in a leap year, with the century exception that let 1900 pass without a 29th and gave 2000 one, since it divides by 400. What has fallen away is the story both entries tell about how February got short. Aiton's says "two days were stolen from it" for July and August, and Collier's has Augustus taking a day from February for his own month; historians of the Roman calendar now regard this as a late legend, since February appears to have had 28 days in the pre-Julian republican calendar, long before either Caesar or Augustus was honoured with a month. The one folk item Aiton's calls merely "local in the United States," Groundhog Day, has since become a national fixture, with Punxsutawney Phil televised each February 2 and a 1993 film that turned the name into a synonym for endless repetition.
Written for this edition, 2026.