Adding 12-month calendar to Doom Emacs; clickable date widget on xmobar.

.config/doom/config.el

@@ -3,6 +3,65 @@
        :desc "List bookmarks" "L" #'list-bookmarks
        :desc "Save current bookmarks to bookmark file" "w" #'bookmark-save))
 
+;; https://stackoverflow.com/questions/9547912/emacs-calendar-show-more-than-3-months
+(defun dt/year-calendar (&optional year)
+  (interactive)
+  (require 'calendar)
+  (let* (
+      (current-year (number-to-string (nth 5 (decode-time (current-time)))))
+      (month 0)
+      (year (if year year (string-to-number (format-time-string "%Y" (current-time))))))
+    (switch-to-buffer (get-buffer-create calendar-buffer))
+    (when (not (eq major-mode 'calendar-mode))
+      (calendar-mode))
+    (setq displayed-month month)
+    (setq displayed-year year)
+    (setq buffer-read-only nil)
+    (erase-buffer)
+    ;; horizontal rows
+    (dotimes (j 4)
+      ;; vertical columns
+      (dotimes (i 3)
+        (calendar-generate-month
+          (setq month (+ month 1))
+          year
+          ;; indentation / spacing between months
+          (+ 5 (* 25 i))))
+      (goto-char (point-max))
+      (insert (make-string (- 10 (count-lines (point-min) (point-max))) ?\n))
+      (widen)
+      (goto-char (point-max))
+      (narrow-to-region (point-max) (point-max)))
+    (widen)
+    (goto-char (point-min))
+    (setq buffer-read-only t)))
+
+(defun dt/scroll-year-calendar-forward (&optional arg event)
+  "Scroll the yearly calendar by year in a forward direction."
+  (interactive (list (prefix-numeric-value current-prefix-arg)
+                     last-nonmenu-event))
+  (unless arg (setq arg 0))
+  (save-selected-window
+    (if (setq event (event-start event)) (select-window (posn-window event)))
+    (unless (zerop arg)
+      (let* (
+              (year (+ displayed-year arg)))
+        (dt/year-calendar year)))
+    (goto-char (point-min))
+    (run-hooks 'calendar-move-hook)))
+
+(defun dt/scroll-year-calendar-backward (&optional arg event)
+  "Scroll the yearly calendar by year in a backward direction."
+  (interactive (list (prefix-numeric-value current-prefix-arg)
+                     last-nonmenu-event))
+  (dt/scroll-year-calendar-forward (- (or arg 1)) event))
+
+(map! :leader
+      :desc "Scroll year calendar backward" "<left>" #'dt/scroll-year-calendar-backward
+      :desc "Scroll year calendar forward" "<right>" #'dt/scroll-year-calendar-forward)
+
+(defalias 'year-calendar 'dt/year-calendar)
+
 (setq centaur-tabs-set-bar 'over
       centaur-tabs-set-icons t
       centaur-tabs-gray-out-icons 'buffer