Possible Clues:

• Day whose child is loving and giving
• Start of many long weekends
• The 13th is considered unlucky
• In may be casual in some places
• Defoe's character following one of Chesterton's, so-called
• Casual day
• End of a work week, for many
• When passport enters brawl?
• Muslim Sabbath
• TGI ... an unusually fair, dry vacation?