Năm 1981 có bao nhiêu ngày Thứ 4

7/1/1981 14/1/1981 21/1/1981 28/1/1981 4/2/1981 11/2/1981 18/2/1981 25/2/1981 4/3/1981 11/3/1981 18/3/1981 25/3/1981 1/4/1981 8/4/1981 15/4/1981 22/4/1981 29/4/1981 6/5/1981 13/5/1981 20/5/1981 27/5/1981 3/6/1981 10/6/1981 17/6/1981 24/6/1981 1/7/1981 8/7/1981 15/7/1981 22/7/1981 29/7/1981 5/8/1981 12/8/1981 19/8/1981 26/8/1981 2/9/1981 9/9/1981 16/9/1981 23/9/1981 30/9/1981 7/10/1981 14/10/1981 21/10/1981 28/10/1981 4/11/1981 11/11/1981 18/11/1981 25/11/1981 2/12/1981 9/12/1981 16/12/1981 23/12/1981 30/12/1981