Russia is closing in on a decision to switch to a night race in 2017, event organisers have said, as part of an effort to attract more fans.
Sochi chiefs have always had one eye on running the event in the evening, but needed to weigh up the costs of installing lighting equipment.
With that feasibility study having been completed, organisers are now edging closer giving the project a green light.
However, with next year's race taking place in May it is too late to make next year's event a night race, so 2017 is looking more likely.
When asked by Motorsport.com about the latest on the night race plans, Krasnodar region representative Alexander Saurin said: "We have calculated how much it will cost, and how long it will take us to prepare the venue.
"So we are analysing the solution. I think we shouldn't expect that before 2017. We will make the decision in 2016 but won't launch the operation until 2017."
Dusk start likely
Sochi consultant Richard Cregan said that he expected the race would run at dusk, which is similar to the timing of the Abu Dhabi Grand Prix that he has also overseen.
"I think something like a 7pm start would make most sense," said Cregan. "That way it could start when it is light and finish in the dark.
"We are looking at what needs to be done, but hopefully the installation of lighting equipment will help us allow Sochi to run as a venue all year round."