Task: Find the latest-arriving one-way economy flight from Denver (DEN) to Las Vegas (LAS) on 2026-06-15.
Hint: Use one-way search, enter Denver (DEN) as the origin and Las Vegas (LAS) as the destination, choose 2026-06-15, choose economy, then compare the visible arrival times manually.
Reference answer: United Airlines flight UA1976, Southwest Airlines flight WN797, departing 6:37 PM and arriving 11:58 PM, 1 stop, total travel time 6h 21m