Date pattern regex
// e.g. 2016-12-10T00:59:09+0100 (19|20)[0-9]{2}[-](0[1-9]|1[0-2])[-](0[1-9]|1[0-9]|2[0-9]|3[0-1])(T)(0[0-9]|1[0-9]|2[0-3]):([0-5][0-9]):([0-5][0-9])(\+|-)(0[0-9]00)