Unexpected keyDown behavior with up/down arrow keys

[panthony]

Copying the "onKeyDown" behavior for a months selector, I noticed that the behavior is quite unexpected when using down/up arrow.

In the following configuration:

Pressing 'Up', you would expect the cursor to either:

• stay in place
• go back to 25

The actual behavior is to go to 01 because of the following line:

let newIndex = Math.max(index - 7, 0);

Instead of working on the days list, maybe it could use the weeks instead to easily navigate on x/y axis.

Bonus
This logic could be abstracted in an utility function to be reused in other context (month selection, split by quarters).

No need to know about 'days', you can simply expect a list of rows/cells with an id and a isDisabled attribute in it.