Git commits in Moodle 3.1.x by Grigory Baleevskiy

commit 53754839d267ce11897891ee837c672ed2412e65
Author: Grigory Baleevskiy <grigory@catalyst-au.net>
Date:   Sun, 31 Jan 2016 09:14:48 +0800
Tag:    v3.1.0-beta

MDL-52978 core_lib: fixed wrong days showing for dates in datepicker