Store today's date in App Connect variable and be able to add/subtract days

I’m working on an appointments feature and want to keep it nice and simple.

I can’t see how to do this in Wappler so would appreciate some tips.

I have created a variable in App Connect called ‘varDate’ and want to set the default value to today.

I have two buttons - ‘Previous’ and ‘Next’. I want these to subtract or add a day to the date in the variable.

In doing this, I can query the data and show the appointments for the selected day.

I thought this would be straight forward and was expecting to see the {{NOW}} option in App Connect but it’s not there. And entering it manually didn’t produce anything.

How should I do this?