Emacs / Generate a month view

org-calendar.el

(defun org-calendar-face (date)
  'default)

(defun org-calendar-generate-month (year month)
  (let* ((first (calendar-day-of-week (list month 1 year)))
         (first (+ (mod (+ (- first 1) 7) 7) 1)) ;; Week starts on Monday
         (last  (+ first (calendar-last-day-of-month month year)))
         (days ""))
    (dotimes (row 6)
      (dotimes (col 7)
        (let* ((index (+ 1 col (* row 7)))
               (day (- index first -1))
               (date (encode-time 0 0 0 day month year)))
          (if (or (< index first) (>= index last))
              (setq days (concat days "   "))
            (setq days (concat days
                (propertize (format "%2d " day)
                            'face (org-calendar-face date)))))))
      (when (< row 5)
        (setq days (concat days "\n"))))
    (concat
     (propertize
      (s-center 20 (format "%s %d" (calendar-month-name month) year))
      'face 'org-calendar-month-header)
     " \n"
     (propertize
      (mapconcat #'(lambda (day)
                     (substring (calendar-day-name day t t) 0 2))
                 '(1 2 3 4 5) " ")
      'face 'calendar-weekday-header)
     " "
     (propertize
      (mapconcat #'(lambda (day)
                     (substring (calendar-day-name day t t) 0 2))
                 '(6 0) " ")
      'face 'calendar-weekend-header)
     " \n"
     days)))