Top 20 NuGet date-picker Packages

Fully customizable calendar for Xamarin.Android with a wide variety of features and displaying modes.
Fancy year and month picker library for Xamarin.Android
A Material design back port of Android's CalendarView
Xamarin.Android library for Date and Time Picker in same dialog
An Android Library to pick dates range, that helps user to select range from future dates.
A styleable DatePicker for Android using the old spinner style (NumberPickers). Don't forget to add "Mono.Android.Export.dll" as reference on your project.
Xamarin Binding Library - FSCalendar