Metadata Menu: Formula Field problem to output number of days until birthday

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1

What I’m trying to do

I’m using the “Metadata Menu” plugin.

I have a note field, Date_of_Birth, which represents a person’s birthday.

I want to configure another field, Days_Before_Birthday, to display the number of days remaining until the next birthday.

I can use a formula field that accepts JavaScript, but my code doesn’t work.

Things I have tried

This code work in a dataviewjs block inside the note:

var startDate = DateTime.fromISO(dv.current().Date_of_Birth).set({
  year: DateTime.now().get("year")
});
var diff = startDate.diffNow().as('day');

if(diff < 0 ) {
	startDate = DateTime.fromISO(dv.current().Date_of_Birth).set({
  year: DateTime.now().get("year") + 1});
  diff = startDate.diffNow().as('day');
}

const diffAbs = Math.abs(diff);
const wholeNumberedDateDifference = Math.round(diffAbs);
dv.span("Birthday is in: " + wholeNumberedDateDifference + " days");

I tried this code in the formula property:

var startDate = DateTime.fromISO(dv.current().Date_of_Birth).set({
  year: DateTime.now().get("year")
});
var diff = startDate.diffNow().as('day');

if(diff < 0 ) {
	startDate = DateTime.fromISO(dv.current().Date_of_Birth).set({
  year: DateTime.now().get("year") + 1});
  diff = startDate.diffNow().as('day');
}

const diffAbs = Math.abs(diff);
const wholeNumberedDateDifference = Math.round(diffAbs);
return wholeNumberedDateDifference;

The field stay empty. :sob: