January 1, 2011 fell on a Saturday.
January the 1st 2011 was on a Saturday.
January 1, 2011 was a Saturday.
It can be on any day [Saturday, January 1, 2011]
January 1 2011 is a Saturday.
1 January 1986 was a Wednesday.
1 January 1980 was a Tuesday.
1 January 1989 was a Sunday.
January 1 1974 was a Tuesday.
1 January 2006 was a Sunday.
1 January 1970 was a Thursday.
1 January 2014 will be a Wednesday.
1 January 2017 will be a Sunday.