Video: https://imgur.com/a/W196T5f
iOS keeps the input on screen, so you can see the value in context. Android covers it up, and shows the value in a different format in the header.
iOS shows the Month+Year inside the calendar, with a blue arrow beside it to indicate interactivity. It’s not a strong affordance, but it’s something.
On Android, nothing gives any such affordance.
Blindly tapping the month+year in the calendar does nothing.
Blindly tapping the day or month on the header does nothing.
The year looks similar to the day and month, only smaller, and slightly darker grey. But if you tap it, you can scroll through the years.
There’s no way to scroll through months – the only option is to tap through them one at a time.