The original timetable for the Singapore GP has been altered to include more night running after teams voiced concerns.
The FIA announced earlier this year that the Singapore race would take place under floodlights at 20:00 hours local time while Friday's second practice session and qualifying would also take place under lights.
However, in addition to the night programme, there would also be a daytime practice session on Friday from 16:00 to 17:30 hours and final practice on Saturday from 17:00 to 18:00 hours.
Some of the teams, though, voiced concerns about the lack of night running, especially after witnessing the first MotoGP race held at night in Qatar.
"At the beginning I was not relaxed but not so worried, but after I saw Qatar and I spent time there, I am not confident 100 percent now. I am talking about the safety of the drivers - because I am not worried about having to work all night if it is for our job," said Toro Rosso's team manager Massimo Rivola. "The safety issue we have to consider more carefully."
Toro Rosso's as well as other teams' concerns have resulted in a changes being made to the Singapore schedule, with all the sessions now taking place at night.
The Revised Turkish GP Schedule
Practice 1 Friday 19:00-20:30
Practice 2 Friday: 21:30-23:00
Practice 3 Saturday 19:00-20:00
Qualifying Saturday: 22:00-23:00
Race Sunday: 20:00