The full timetable for Fernhill Fields 2027 is out (sample). Every stage is a lane, and every set is as long as the band plays.
Read along a lane to follow one stage through the day. Read down the page to see what plays at the same time: two blocks above each other are a clash, and you will have to choose.
The gaps between blocks are changeovers. Most are thirty minutes, which is enough to walk from the Big Top to the Hill Stage and still get a drink.