Following function will check if input date is entered in DD/MM/YYYY format, It also validates a minimum date that can be entered to an input field (original code from here)
function IsValidDate(inputDate) {
const regex = /^\d{2}\/\d{2}\/\d{4}$/;
var minDate = new Date("01/01/1900 12:00:00");
if (inputDate.match(regex) === null) {
return false;
}
const [day, month, year] = inputDate.split('/');
const isoFormattedStr = `${year}-${month}-${day}`;
const date = new Date(isoFormattedStr);
const timestamp = date.getTime();
if (typeof timestamp !== 'number' || Number.isNaN(timestamp)) {
return false;
}
if (isoFormattedStr < minDate.toISOString()) {
return false;
}
return date.toISOString().startsWith(isoFormattedStr);
}