Function: decoded-time--alter-month

decoded-time--alter-month is a byte-compiled function defined in time-date.el.gz.

Signature

(decoded-time--alter-month TIME INCREASE)

Documentation

Increase or decrease the month in TIME by 1.

Source Code

;; Defined in /usr/src/emacs/lisp/calendar/time-date.el.gz
(defun decoded-time--alter-month (time increase)
  "Increase or decrease the month in TIME by 1."
  (if increase
      (progn
        (cl-incf (decoded-time-month time))
        (when (> (decoded-time-month time) 12)
          (setf (decoded-time-month time) 1)
          (cl-incf (decoded-time-year time))))
    (cl-decf (decoded-time-month time))
    (when (zerop (decoded-time-month time))
      (setf (decoded-time-month time) 12)
      (cl-decf (decoded-time-year time)))))