In the great gatsby Fitzgerald uses ages and dates to reflect the themes and ideas.?

Fitzgerald married Zelda shortly after WWI (1918), but the other date/age is irrelevant because the book was published April 10, 1925, Nicks birthday is to show how the importance of age diminishes as you grow older, and Nick and Daisy do not consummate their love, that would be incest, Daisy and Gatsby consummate their love.