calculateCellforDate.js

let timeOfJustNow = new Date();
let dayInMonth = timeOfJustNow.getDate();
let monthInYear = timeOfJustNow.getMonth()+1;


let sheetName = 'Ark 8'; // put the name of your tab in your sheet

let startingColumnChar = 'D'; // set your coumn character for January 
let startingRowNbr = 2;       // set your starting row for the first day in month 

// calulating the column based on monthNumber
let column = String.fromCharCode( columnChar.charAt(columnChar) + monthInYear);

let calulatedCellReference = sheet + "!"+ column + startingRowNbr + dayInMonth;

return cellNbr;