Action/Adventure:
* Day of the Dead (1985)
* The Day After (1983)
* Doomsday (2008)
* The Day the Earth Stood Still (1951, 2008)
* The Day the Clown Cried (1972)
Comedy:
* The Day I Met My Father (2003)
* The Day the Earth Stood Still (1951, 2008)
* The Day After Tomorrow (2004)
* My Big Fat Greek Wedding (2002)
* The Day After (1983)
Drama/Romance:
* The Day the Earth Stood Still (1951, 2008)
* My Big Fat Greek Wedding (2002)
* The Day the Clown Cried (1972)
* The Day I Met My Father (2003)
* The Day After Tomorrow (2004)
Horror:
* Day of the Dead (1985)
* The Day After (1983)
* Doomsday (2008)
* The Day the Earth Stood Still (1951, 2008)
* The Day the Clown Cried (1972)
Science Fiction:
* The Day the Earth Stood Still (1951, 2008)
* The Day After Tomorrow (2004)
* Doomsday (2008)
* The Day After (1983)
Other:
* A Day in the Life (1992)
* One Day (2011)
* Good Day for Dying (1996)
* National Lampoon's Vacation (1983)
Note: This is not an exhaustive list, there are many more movies with "day" in the title. You can find more movies by searching online databases like IMDb or Rotten Tomatoes.