Check for package upgrades every Monday morning

init.el

@@ -640,6 +640,7 @@
 (load "jekyll.el")
 (load "enclose-string.el")
 (load "buf-manipulation.el")
+(load "package-manip")
 
 ;; Define aliases
 (defalias 'yes-or-no-p 'y-or-n-p)
@@ -748,3 +749,6 @@
        (171 187)    ; «»
        (187 171)    ; »«
       ))
+
+;; Check for package upgrades every Monday so I don’t forget.
+(check-for-package-upgrades-on-day 1)

lisp/package-manip.el

@@ -0,0 +1,102 @@
+;;; package-manip.el --- Utility functions to check if package upgrades are available
+
+;;; Commentary:
+;; I should add one.
+
+;; Credits go to http://emacs.stackexchange.com/a/16407/507
+
+;;; Code:
+
+(defun package-upgrade-all ()
+  "Upgrade all packages automatically without showing *Packages* buffer."
+  (interactive)
+  (package-refresh-contents)
+  (let (upgrades)
+    (cl-flet ((get-version (name where)
+                (let ((pkg (cadr (assq name where))))
+                  (when pkg
+                    (package-desc-version pkg)))))
+      (dolist (package (mapcar #'car package-alist))
+        (let ((in-archive (get-version package package-archive-contents)))
+          (when (and in-archive
+                     (version-list-< (get-version package package-alist)
+                                     in-archive))
+            (push (cadr (assq package package-archive-contents))
+                  upgrades)))))
+    (if upgrades
+        (when (yes-or-no-p
+               (message "Upgrade %d package%s (%s)? "
+                        (length upgrades)
+                        (if (= (length upgrades) 1) "" "s")
+                        (mapconcat #'package-desc-full-name upgrades ", ")))
+          (save-window-excursion
+            (dolist (package-desc upgrades)
+              (let ((old-package (cadr (assq (package-desc-name package-desc)
+                                             package-alist))))
+                (package-install package-desc)
+                (package-delete  old-package)))))
+      (message "All packages are up to date"))))
+
+(defun check-todays-package-upgrade-p (&optional no-save)
+  "Check if automatic package upgrade has been performed today.
+
+This function reads the date of the last check from the
+\"last-package-upgrade\" file. Where this file is looked for is
+guessed as follows:
+
+If `user-emacs-cache-directory' is set (e.g. by the
+`xdg-paths.el' package available from
+https://github.com/tomprince/xdg-paths-el), the timestamp file is
+opened from there. Otherwise, it will be read from
+`user-emacs-directory'
+
+If NO-SAVE is 'nil', the current date will be saved to the
+timestamp file.
+
+The return value of this function will be 't' if the timestamp
+file contains todays date, 'nil' otherwise."
+
+  (let ((tsfile-location (if (boundp 'user-emacs-cache-directory)
+                             user-emacs-cache-directory
+                           user-emacs-directory)))
+    (unless (and (file-exists-p tsfile-location)
+                 (file-accessible-directory-p tsfile-location))
+      (make-directory tsfile-location t))
+
+    (let ((timestamp-today t)
+          (timestamp-buffer (find-file-literally
+                             (expand-file-name "last-package-upgrade"
+                                               tsfile-location))))
+      (with-current-buffer timestamp-buffer
+        (goto-char 0)
+        (unless (looking-at-p (format-time-string "%Y-%m-%d"))
+          (unless no-save
+            (erase-buffer)
+            (insert (format-time-string "%Y-%m-%d"))
+            (save-buffer 0))
+          (setq timestamp-today nil))
+        (kill-buffer)
+        timestamp-today))))
+
+(defun check-for-package-upgrades-on-day (&optional day-number)
+  "Check for package upgrades if today is DAY-NUMBER.
+
+DAY-NUMBER can be anything between 0 and 7, inclusive.  Both 0
+and 7 denote Sunday to make both types of users happy.
+
+If DAY-NUMBER is 'nil', it defaults to today's day."
+
+  (let ((actual-day-number (cond
+                            ((eq day-number nil) (string-to-number (format-time-string "%u")))
+                            ((eq day-number 0) 7)
+                            (t day-number))))
+    (when (and (eq day-number (string-to-number (format-time-string "%u")))
+               (not (check-todays-package-upgrade-p t)))
+      (message "Calling")
+      (when (call-interactively 'package-upgrade-all)
+        (message "Called")
+        (check-todays-package-upgrade-p nil)))))
+
+(provide 'package-manip)
+
+;;; package-manip.el ends here