Changing Date text instead of picking from Date picker doesn't trigger OnChange event Date field in CRM 365

I have a simple Javascript that checks that a Date of Birth entered in the date control is valid - no future date allowed or date before 01/01/1900. When the date is selected from the date picker the function works and triggers the onchange event but when a valid date text e.g. 01/01/1890 is entered into the field the function does not trigger. Has anyone experienced or resolved this before please?