Gravesites are marked with flags on Memorial Day at the Evergreen Cemetery in Harvest West Park in Santa Cruz Monday. Previously known as Decoration Day, it is a federal holiday in the U.S. designed to honor and mourn military personnel who died while serving in the armed forces. Memorial Day also marks the unofficial start of summer in the U.S.—which officially starts June 20. Some confuse Memorial Day with Veterans Day (Nov. 11), which is set aside to celebrate those who have served or are serving in the U.S. military. Evergreen, established in 1850, is owned by the Santa Cruz Museum of Art & History, said docent Kate Clark.