At UTC time Thursday 10:15 , for example , it is Wednesday 23:15 in Samoa , which is eleven hours behind UTC , and it is Friday 00:15 in Kiritimati ( separated from Samoa by the IDL ) , which is fourteen hours ahead of UTC . At UTC time Thursday 10:15 , for example , it is Wednesday 23:15 in Samoa , which is eleven hours behind UTC , and it is Friday 00:15 in Kiritimati ( separated from Samoa by the IDL ) , which is 14 hours ahead of UTC .