You can use month and year props instead. For example:

<v-date-picker v-model="date" :month="9" :year="2023" />

displayValue is just a side-effect of VDatePicker calling makeVDatePickerMonthProps that calls makeCalendarProps and would actually be redundant if anyone would try to implement it.

Using month and year props works but the behavior is not yet quite what we had before: VDatePicker effectively displays the passed in month and year but once the model-value changes, I expect the VDatePicker to display the model-value date instead of the values passed to month and year.

Also, there's currently (to my understanding) no prop for setting the day as month and year.

I can see the value of having control over year and month when we show up the picker, but I don't really see much of a benefit of having full external control over a component that exists to get input from the user and disappear once it's done.

This demo shows that in order to re-apply month and year you'd have to reset the picker. All you really lose is transition animation (can be kinda supplemented with <v-*-transition> wrapper, but won't be exactly the same).

Introducing day would bring nothing to the table except possibility for bugs and forcing us to make rounding decisions (e.g. is 31th of February just 28th (or 29th) or should it become 2nd (or 3rd) of March). If you can explain how it would work and give usage examples, that would be a material for separate feature request.