How the planner finds it
- A leg counts as overnight when it departs in the evening, arrives on the next calendar day, and lasts at least six hours — after 17:30 and landing by 13:00 for flights, after 18:00 for trains, buses and ferries.
- Every overnight leg is counted, and each is worth one night at your nightly rate: $50 per person by default, editable up to $500.
- The optimizer subtracts that from the leg's effective price, so an overnight option wins whenever it costs at most a night's worth more than the alternative.
- The plan then states the total plainly: how many nights you sleep in transit and roughly what that was worth.
- Turn the switch off and the same legs are still found and labelled — they just stop getting a price advantage.
Worked example
What the nightly rate did to the example plan
from the example plan- Overnight coach, London → Paris
- $45 per person
- Hotel night avoided, at the default rate
- −$50 per person
- Effective cost to the optimizer
- −$5 per person
- Overnight legs on the whole plan
- 2, worth about $100 per person
A leg that costs less than a night in a bed is free travel, which is why the plan sometimes prefers a slower one. Raise the nightly rate if you stay somewhere expensive and more overnights win; set it to zero and none do.
When it does not work
- A night in a coach seat is not a night in a bed. If you cannot sleep sitting up, the $50 is not real money to you.
- You arrive early, tired, and usually before check-in — so you may pay for the previous night anyway just to have a room at 8am.
- Overnight flights count as departing on their date, at day granularity, which can shift a night on paper against how it feels.
- An overnight gap between two separate tickets is not a saved hotel night. It is a gap you have to survive, and it is badged as risk, not as a saving.
Risk
Low risk
The only thing you are gambling is a night's sleep.