What day of the week was May 22, 1915?

The day of the week May 22nd, 1915 fell on was a Saturday.

Lassen Peak erupts with a powerful force the and is the only mountain other than Mount St. Helens to erupt in the contiguous US during the 20th century. Three trains collide in the Quintinshill rail disaster near Gretna Green the Scotland, killing 227 people and injuring 246; the accident is found to be the result of non-standard operating practices during a shift change at a busy junction.