=TEXT(DATE(2021; 1; -3 + 7 * SPLIT( LOWER($A2) ; "abcdefghijklmnopqrstuvwxyz " ) - WEEKDAY(DATE(2021; 1; 4); 2) + 1); "dd.mm.yyyy 00:00")
=TEXT(DATE(2021; 1; -3 + 7 + 7 * SPLIT( LOWER($A2) ; "abcdefghijklmnopqrstuvwxyz " ) - WEEKDAY(DATE(2021; 1; 4); 2)); "dd.mm.yyyy 23:59")
Not all would be necessary just for the date range, but I wanted to write "CW XYZ" and needed the time as well for some calculation