Tour Date Problems

my site is https://casinojunketclub.com and when you go to Scheduled Trips: then By Date the dates are out of order.
The fix I found for it was to put the post dates in order. The problem is that if I have a trip on January 1 and I originally added it December 1 then a week later I add a trip for December 15th the dec 15th trip is posted after the January 1 trip because the post date is later.

Is there any way it could be posted by the date of the trip instead of the post date? Thank you.