Ascension of Baha'u'llah Boston Pops (First week in May through middle of July) First Monday Trade Days (Thursday through Sunday before first Monday of each month) Flores de Mayo (May)Celebrated in: El Salvador, Philippines Founder's Day Garland Day (May 12; May 29) National Family Month (Second Sunday in May through the third Sunday in June) National Reconciliation Week (May 27-June 3) Shick-Shack Day