All 15 hacks
Hack 02 of 15 · The shape of the trip

Cheaper days

Moving one flight by a couple of days — letting one city get longer while the next gets shorter — can drop that leg's fare without changing the trip you are taking.

No riskFree fare gridsOne-tap re-planNights spelled out
How the planner finds it
  1. Before the optimizer runs, every city pair on your route is priced on every day of your window from two free grids: Kiwi's date-range search (one call per nine-day chunk) and Ryanair's own cheapest-fare-per-day calendar for the routes it flies.
  2. Once the plan is built, each flight leg is re-read out of that grid three days either side of the date it landed on.
  3. A move is only reported when it saves at least $12 and at least 10% of that leg's fare, and only the single best move per leg is shown.
  4. The consequence is stated in nights, not dates: “Madrid 4 nights instead of 3”. The city before the moved flight gets longer, the city after gets shorter.
  5. Moves that push a city under one night, collide with the leg before or after, or land you home after your return date are dropped. A move that leaves the nights range you set is still shown, labelled as leaving it.
  6. One tap re-plans the whole trip with those nights, reusing the fares already found, so it takes seconds rather than another full search.
Worked example
One leg, three days later
example output
Flight
Madrid → London, moved from the 8th to the 11th
Fare
$126 → $86
Saving
−$40 per person
Cost in nights
Madrid 4 instead of 3, London 2 instead of 3

The optimizer already picked the cheapest dates inside the nights you allowed. What is left in this section is the trade you never authorised it to make — so it asks instead of taking it.

When it does not work
  • Fixed dates with tight nights ranges leave nowhere to move. The section will be empty and will say so.
  • The grids only cover pairs Kiwi and Ryanair price. A leg neither covers gets no cheaper-days check at all.
  • Savings under $12, or under 10% of the fare, are not shown. Chasing $6 across six legs is not worth a re-plan.
  • Grid fares are cached up to 12 hours and are not a booking. The re-plan re-checks the legs that matter.
Risk
No risk

One booking, normal rules. Nothing here can be taken away from you.

On your plan: “Cheaper days”, directly under your route, with a one-tap re-plan on every row.flexible datesfare calendarcheapest day to fly
Keep reading

The rest of “The shape of the trip”

One booking, normal rules. Nothing here can be taken away from you. Every hack on the list gets the same treatment: how it is found, a worked example, and the catch.

See it on a real trip

Give it your cities.

Two trips free. It runs all 15 of these, tells you which ones found nothing, and stamps every price verified, cached or estimate.