Everything after it moves, and nothing you set yourself should. Change one stop and every arrival and departure the plan worked out for you re-times from that point on. The stays you chose, the times you pinned and the order you picked stay exactly as you left them.
That's the short version. The longer one is worth knowing, because "one small change" is how most hand-made trip plans quietly go wrong. Here is what each kind of change does, and what to check afterwards.
Why does one change move everything after it?
Because most of the times in a trip plan are results, not entries. You chose the hotel. The plan worked out that you'll arrive at 19:40, by adding the drive to the moment you left the stop before, and that departure is itself a result of how long you stayed.
So every stop sits at the end of a chain. Touch one link and every link after it shifts. In a spreadsheet you redo that arithmetic by hand, row by row, and the row you forget is the one that books you into a hotel a day early.
What happens when you add a stop?
One drive becomes two. The leg from A to C is replaced by A to B and B to C, and the time you spend at B is added on top. Every arrival after B moves later by the detour plus the stay.
The thing to check is where it landed. "Between Trento and Verona" should mean between Trento and Verona, not at the end of the day. Fernweh places a new stop against the order you were looking at when you chose the spot, and it shows you the new route before you commit. The route you saw in that preview is the one it saves.
What happens when you remove a stop?
The reverse. Two drives close up into one, the time you would have spent there comes back, and everything after it moves earlier.
There is one removal that does more than that: the night. Delete the stop where you were sleeping, and the stops that sat on the next day have no night to wait for. They pull back into the day before. In Fernweh, if you do that from a Day view, the plan tells you which stops moved and to which day.
Why doesn't a change on Tuesday move Wednesday?
Because a night resets the clock. When you stay somewhere for a night, the next morning starts at the time you set out each day, not at "whenever you arrived, plus twelve hours". So an extra stop on Tuesday afternoon moves Tuesday evening's arrival at the hotel. As long as you still get there that evening, Wednesday leaves at the same time it always did.
This is the most useful thing to know about multi-day plans. Each night is a firewall. A change spreads to the end of its day and stops there. If a change seems to have moved the whole rest of the trip, it crossed a day: either it added or removed a night, or it pushed a stop onto another day.
In Fernweh the morning time is one setting for the whole trip, and every overnight stop you haven't pinned yourself leaves at it. Change that one setting and every morning moves together.
What happens when you make a stay longer?
It depends on how you said it. A stay can be a length of time (forty minutes at a charger, three hours in a town) or a number of nights.
Lengthen a stay in time, and the rest of that day moves later by exactly that much. A stay shorter than a night is never snapped to the next morning: an extra hour is an hour, not "leave tomorrow". Add a night, and the following morning becomes the one after.
A long stay in hours can still run past midnight. The day changes with the calendar, but the plan doesn't start calling it a night you never booked.
What happens when you reorder stops?
The drives on both sides of every moved stop are worked out again for the new sequence, and the times follow. The stops you didn't move keep their places. In Fernweh, reordering within a day changes only that day's order. If the new order makes the day spill into the next one, you're told.
What if the change breaks a time you pinned?
Some times aren't results: the ferry at 14:20, the check-in window, the tour you booked. If a change upstream means you can't make one of those, the plan should say so before the day, not quietly move your time to one it likes better. We wrote about this in who owns the numbers in your trip plan. In short, Fernweh paces the day leading up to a pinned arrival using only the times it chose itself. If that isn't enough, it flags the stop: "Cannot arrive in time".
What if the change leaves a hole?
Remove a two-night stop from the middle of a trip whose last hotel is booked, and there may now be a day with nothing in it. A good plan shows that gap rather than hiding it. It shouldn't stretch a stay you set to fill the time either: two nights should stay two nights.
In Fernweh that shows up as its own row in the trip, "1 unplanned day" or "3 unplanned days", with the dates it covers. Whether you fill it, drop it or leave it as a free day is your call.
What should a planner never move when you change a stop?
Four things, whatever tool you use:
- The stays you set. Two nights is two nights; forty minutes is forty minutes.
- The times you pinned. If they can't be met, the plan says so instead of moving them.
- The order you chose. A stop goes where you put it.
- The time you set out each morning. One setting, kept until you change it.
Everything else is arithmetic, and arithmetic should redo itself every time. To test any planner, make one change in the middle of a trip, then check those four things and look for the first stop on the next day. If something you typed has moved, the plan has stopped being yours.
The short answer
One change moves everything after it, up to the next night. A plan worth trusting redoes the arithmetic for you, shows you what crossed into another day, and leaves alone every number you typed.
Fernweh behaviour described here reflects version 1.25.0 for iOS. The day notices described are the ones shown when you edit from a Day view. Header photo by Aleksandr Dalakian on Unsplash.