Singapore doesn't observe daylight saving time but Porto does. DST in Porto started on 31 March 2019 and will end on 27 October 2019. Once DST ends in Porto the time difference between Porto and Singapore will be 8:0 hours.
Time zone: WEST - Western European Summer Time (UTC/GMT +1)DST started on 31 March 2019DST will end on 27 October 2019Time zone difference / Flight distance
Time zone: SGT - Singapore Time (UTC/GMT +8)Time zone difference / Flight distance