Next / Previous Date external controls

Hello

I've currently got a set up to change the date by +/- 1 day based on a previous and next button. It's not really elegant, just adds or subtracts 1 day from the current date and updates the picker.

I was wondering if there's a more elegant solution as I need to be able to get the next/previous available date - as I'm disabling all dates, and only showing a select few (i.e. http://amsul.ca/pickadate.js/date/#disable-dates-all)

Any help appreciated.

Thanks