The day selected in the DayPickerInput is changed to year in specific format (DD-MM-YY)

[Pravallikakotha]

I have reproduced in the CodeSandbox linked below
https://codesandbox.io/s/react-day-picker-selectbox-year-month-ig-3nr7z

it's working in the format DD/MM/YY but in DD-MM-YY it is working weird

In order to reproduce the issue take the following steps:

1. Click the DayPickerInput and select any date in the DayPicker component, e.g. 12-03-20 (12th
   march 2020)
   2 . DayPickerInput disappears after selecting a date
2. Open DayPickerInput again and select any date in the same month without changing the month
   and year eg. 23-03-20, now it changes to 23-03-12