How many times has Mother's Day been on May eighth?

In some countries it has not fallen on the 8th of May at all, as it is not in May. Different countries have it at different times of the year. In countries where it is on the second Sunday in May, since 1938 it has fallen on the 8th of May in 1938, 1949, 1955, 1960, 1966, 1977, 1983, 1988, 1994, 2005 and 2011. It will next be on the 8th of May in 2016.