Two-day rallies are an increasing possibility if the World Rally Championship's expansion brings it back to a 16-round calendar.
Chile and Japan are among countries interested in WRC dates, and series promoter Oliver Ciesla wants the calendar to grow from its current 13-round mark to 15/16.
The WRC featured 16 rounds from 2004-07 but then cut back due to the financial and logistical burden that was creating on teams.
Mindful of this, Ciesla said trimming events from the current standard three-day duration could be an answer.
"We do not exclude shortening the rallies, but I see it in the bigger strategic context with 14, 15 or 16 rallies," he told Autosport.
"If we are talking about [shortening] one or two rallies, it wouldn't make much difference, but if we shorten them all then this can save 15 or 16 times one day - that's more than two weeks in a hotel. Then we are talking."
The schedule was supposed to move up to 14 rallies in 2016, but the last-minute loss of China meant it remained at 13.
Despite 14 being the target for 2018, the calendar will be 13 rounds again with Poland being dropped just as Turkey returned.
Some WRC events have already indicated they would like to run a two-day format in 2018.
Ciesla said he was not against that, but it would be dealt with on a rally-by-rally basis.