Singapore doesn't observe daylight saving time but Tehran does. DST in Tehran started on 22 March 2019 and will end on 22 September 2019. Once DST ends in Tehran the time difference between Tehran and Singapore will be 4:30 hours.
Time zone: IRDT - Iran Daylight Time (UTC/GMT +4:30)DST started on 22 March 2019DST will end on 22 September 2019Time zone difference / Flight distance
Time zone: SGT - Singapore Time (UTC/GMT +8)Time zone difference / Flight distance