diff --git a/init.d/basics/global-variables.el b/init.d/basics/global-variables.el
index b704a83..7d2b7b9 100644
--- a/init.d/basics/global-variables.el
+++ b/init.d/basics/global-variables.el
@@ -1,6 +1,6 @@
-;;; global-variables.el --- Set global variables. -*- lexical-binding: t; -*-
+;;; global-variables.el --- Set some global variables. -*- lexical-binding: t; -*-
 
-;; Time-stamp: <2020-02-26T04:52:33+0100>
+;; Time-stamp: <2020-02-26T22:56:29+0100>
 
 ;;; Commentary:
 ;; * Set `slow-computer'.
@@ -9,6 +9,8 @@
 ;; * Fewer startup messages.
 ;; * Configure backup settings.
 ;; * Set username and email-address.
+;; * Set up authentication sources
+;; * Define some essential functions.
 
 ;;; Code:
 
@@ -63,6 +65,11 @@
     "Returns the version of clangd as float."
     (string-to-number
      (nth 2 (split-string (shell-command-to-string "clangd --version")))))
+
+  (defun my/file-last-modification (file)
+    "Return the absolute time FILE was last modified in seconds."
+    (time-to-seconds
+     (file-attribute-modification-time (file-attributes file))))
   )
 
 (provide 'basics/global-variables)