Button to change the day of a calendar picker

[Dive1]

Hello I have a date picker with two button, one button to move forward one day and the other to move back a day but I can't do a good function to make it work, I have set two var for the two button  true to move foward and false to move back and i've put this in my date picker default date 

Switch(varThisDay;
true; Date(Year(Today());Month(Today());Day(Today()));
false; DateAdd(Date(Year(Today());Month(Today());Day(Today())); -1; Days))

but It don't work like I want, for exemple today is the 17 but when I click and the button to move foward it does nothing because it is set to go at today and the button to move back just move back one day and dont move back again if I want to go at the day 15

and I don't find how to maki this work

[RandyHayes · Accepted solution]

@Dive1 

Set the OnSelect of your forward button to:

    UpdateContext({lclDate: DateAdd(Coalesce(lclDate, Today()), 1)})

Set the OnSelect of your backward button to:

    UpdateContext({lclDate: DateAdd(Coalesce(lclDate, Today()), -1)})

Then set the DefaultDate on your date chooser to:

    Coalesce(lclDate, Today())

I hope this is helpful for you.

[Dive1]

Thank you it works