What do you think would be the preferred way of handling invalid date input on a desktop GUI?
Let's say the user needs to set a date range, e.g. for a search. And he sets the start date to 2018-06-01 and the end date to 2018-05-02, i.e. the end date is before the start date.
Alternative number 1 is that the system auto correct the end date, to the same date as the start date. There might be a highlighting animation informing the user that something was changed (however, he might miss it if he does not look at that input during that second).
Alternative number 2 is that we just display an error message, and the user will have to correct the error himself.