Năm 1980 có bao nhiêu ngày Thứ 5

3/1/1980 10/1/1980 17/1/1980 24/1/1980 31/1/1980 7/2/1980 14/2/1980 21/2/1980 28/2/1980 6/3/1980 13/3/1980 20/3/1980 27/3/1980 3/4/1980 10/4/1980 17/4/1980 24/4/1980 1/5/1980 8/5/1980 15/5/1980 22/5/1980 29/5/1980 5/6/1980 12/6/1980 19/6/1980 26/6/1980 3/7/1980 10/7/1980 17/7/1980 24/7/1980 31/7/1980 7/8/1980 14/8/1980 21/8/1980 28/8/1980 4/9/1980 11/9/1980 18/9/1980 25/9/1980 2/10/1980 9/10/1980 16/10/1980 23/10/1980 30/10/1980 6/11/1980 13/11/1980 20/11/1980 27/11/1980 4/12/1980 11/12/1980 18/12/1980 25/12/1980