var str = 'On the 03/09/2015 I am swiming in a pool, that was build on the 27-03-1994';
var res = str.match(/d{2}([/.-])d{2}1d{4}/g);
document.getElementById('out').value = res;
var str = 'Test Client wants to reschedule your call from 2021-02-18 06:30:00+00:00 to 2021-02-18T07:00';
var res = str.match(/d{2}([/.-])d{2}1d{4}/g);
document.getElementById('out').value = res;