The Southern 100 Road Races were first held in 1955
The first practice session for the Southern 100 International Road Races was affected by the prevailing weather conditions on Monday evening.
The Clerk of the Course, Phil Taubman made the decision that the opening practice session would go ahead and be untimed, whilst conditions permitted.
The timed practice session will now take place prior to Tuesday evening's racing schedule.
It means the third race will now be moved to Wednesday.
The actual timetable of events for Tuesday and Wednesday along with Championship Day on Thursday will be announced on Tuesday afternoon.
Roads around the 4.25 mile Billown circuit will still close at 1805 BST as planned and re-open at 2140 BST.