Off topic, but I can't resist.

The placement of the apostrophe in the menu, i.e. "Today's Posts" is correct. It's about the posts that were submitted today. It is a singular possessive. Placing the apostrophe after the ending "s" would only be required if the word that the possessive applies to is a plural, e.g.

This apple has a core. It is the apple's core (one apple).
There are three apples on the table. I've cut out all the cores. In this bowl, you see the apples' cores (many apples).

"Today" is singular, hence the possessive is "today's". Same applies to "yesterday" and "tomorrow". These are singular forms, unless you're Shakespeare ("... and all our yesterdays have lighted fools the way to dusty death ..." (Macbeth))

cheers,