does valentine's day have an apostrophe
1 Make sure you include a possessive apostrophe in âValentineâs Dayâ. 2  The day is named for Saint Valentine, so it âbelongsâ to him. ( 3 Check our guide to apostrophe usage if youâre not sure why this matters.) Modern usage generally drops the âSaintâ or âStâ prefix, though you can throw it in if you like.