Ds3231 adjust the time using pushbutton

[snowman7807]

Hello,
I have been using the attached code to build an stand alone alarm clock. I have written all the subroutines to adjust each time parameter individually ie, year month, day etc.. . I know how to set the entire clock using the set time function, but I need to know how to adjust each one individually. I am not sure create the selected variable and adjust by 1 when instructed by the +/- configured buttons. Thanks so much in advance