The fulldate format in angular-locale_th-th.js and angular-locale_th.js are wrong.
Current value is "fullDate": "EEEE\u0e17\u0e35\u0e48 d MMMM G y",

Example :

{{landingViewModel.bookingInfo.checkIn | date : 'fullDate'}}

It will generate a date like this "วันพุธที่ 17 ธันวาคม G 2014",
which the G letter should be "พ.ศ." if year is 2557 Buddhist Era (BE)
and for A.D. 2014 it should be "ค.ศ."
or you can remove the G letter it will correct as well.