What day of the week was June 16, 1816?

The day of the week June 16th, 1816 fell on was a Sunday.

Lord Byron reads Fantasmagoriana to his four house guests at the Villa Diodati the Percy Shelley, Mary Shelley, Claire Clairmont, and John Polidori, and inspires his challenge that each guest write a ghost story, which culminated in Mary Shelley writing the novel Frankenstein, John Polidori writing the short story The Vampyre, and Byron writing the poem Darkness (poem)|Darkness.