It was a bit of a hassle but I finally did it. The FT Calendar plugin (version 1.0.6) was starting the week from Sunday, which was rather annoying for me, being a Bulgarian… so I hacked it in order to start from Monday. That works for the thumb calendar shortcode. I just didn’t have the time to work around the whole thing, but it should be pretty easy, having achieved this little victory.
Installation of the „patch“ is actually replacing the existing class-shortcodes.php file with the one, attached here. It’s located in your plugins dir, probably wp-content/plugins/ft-calendar/classes/. DO make sure your plugin is version 1.0.6, or you might wipe out something useful or totally break it! I take no responsibility on the stuff you did or will do after downloading the patch.
Any feedback is welcome!