The moon has not been sighted in Saudi Arabia today and so insha-Allah Ramadan 1439 will commence on the night of Wednesday 16th May 2018. Therefore the first taraweeh will be on Wednesday after Isha salaah and the first fast will be on Thursday 17th May 2018.
May Allah accept our fasting, taraweeh, and all other ibadah that we perform during this special month and grant us the special blessing that it contains. Ameen.
See also: Ramadan and Taraweeh and Timetable