Two children, one car: spotting what you cannot make in time
A clash between siblings is rarely caused by overlapping times — it is caused by not having enough time to travel between places. It can be spotted at entry: if the same adult is driving both children and there are not enough minutes between the two, it does not work, even when the times do not overlap.
Overlapping times is a weak test
Classic conflict detection compares start and end. In family logistics something else decides: when you have to leave. Piano finishes at 15:30 on one side of town, swimming starts at 16:00 on the other. The times do not overlap by a single minute, and one person still cannot do both.
That is why travel time belongs in the calculation. The occupied slot does not begin when the activity begins; it begins when you set off for it.
Two different problems, two different answers
When two activities clash but each has a different driver, that is information: today needs two cars or two people. When the same person is listed for both, it is an error to fix before it happens.
The second case appears easily and quietly — activities are entered separately, at different times, and nobody sees them side by side until the day they collide.
- Same person in two overlapping activities: an error to fix.
- Two activities at once with different people: information to plan around.
- Back-to-back activities: fine, provided there is time to travel.
Warn, do not block
The app does not know everything. Grandma may be arranged, the two places may be on the same street, the session may be cancelled. A clash therefore belongs among warnings, not prohibitions — and it has to be visible on both entries, because a parent looks at the one they are dealing with.
The value is not in the app saying no. It is in the problem showing up in August while you are entering it, rather than at 15:40 on a Tuesday when nothing can be done.
Common questions
What if travel time is only an estimate?
It is. That is why this is a warning rather than a block. Even a rough estimate catches the cases where the gap is ten minutes against an hour of driving.
Does it help with an only child?
Yes, just less often. Typically when an activity collides with a family event, or when one parent has committed to two places in the same evening.
What do I do when a clash is real?
The quickest fix is usually changing who drives for one of them. That is why it should be possible straight from the row, without opening the full form.