Năm 1981 có bao nhiêu ngày Thứ 5

1/1/1981 8/1/1981 15/1/1981 22/1/1981 29/1/1981 5/2/1981 12/2/1981 19/2/1981 26/2/1981 5/3/1981 12/3/1981 19/3/1981 26/3/1981 2/4/1981 9/4/1981 16/4/1981 23/4/1981 30/4/1981 7/5/1981 14/5/1981 21/5/1981 28/5/1981 4/6/1981 11/6/1981 18/6/1981 25/6/1981 2/7/1981 9/7/1981 16/7/1981 23/7/1981 30/7/1981 6/8/1981 13/8/1981 20/8/1981 27/8/1981 3/9/1981 10/9/1981 17/9/1981 24/9/1981 1/10/1981 8/10/1981 15/10/1981 22/10/1981 29/10/1981 5/11/1981 12/11/1981 19/11/1981 26/11/1981 3/12/1981 10/12/1981 17/12/1981 24/12/1981 31/12/1981