These changed back in Emacs 23, and the compatibility aliases don't
exist in Emacs 26 (why?!).
(months ["Chaos" "Discord" "Confusion"
"Bureaucracy" "Aftermath"])
(day-count [0 31 59 90 120 151 181 212 243 273 304 334])
- (year (- (extract-calendar-year date) 1900))
- (month (1- (extract-calendar-month date)))
- (day (1- (extract-calendar-day date)))
+ (year (- (calendar-extract-year date) 1900))
+ (month (1- (calendar-extract-month date)))
+ (day (1- (calendar-extract-day date)))
(julian (+ (aref day-count month) day))
(dyear (+ year 3066)))
(if (and (= month 1) (= day 28))