Age Calculator App using HTML CSS and JS

Calculating age where the day of birth value is higher than the current day value.

I was struggling to get a valid age when the day of birth was bigger than the current day value. Ex: if current day is 27 and the day of birth was 28 I was getting -1 days as result, if 29 result -2, if 30 result -3 etc. How did you managed this issue if you had it? The way I resolved it is to get the last day from the previous month and to subtract the day value that initially resulted.

if (ageInDays < 0) {
// Adjusting the age in months and days when the birthdate's day is greater than the current date's day
ageInMonths -= 1;
const lastMonthDate = new Date(
currentDate.getFullYear(),
currentDate.getMonth(),
0
); // This gets the last day from the previous month by adding 0 as para for day
ageInDays += lastMonthDate.getDate();