how to hide post author and post date UPDATE

A year ago, what worked was adding this to your theme’s css:

.postmeta { display: none; }

But now, the name changed and it’s called:

.entry-meta{ display: none; };

Enjoy!

Alternative:

You can use the CSS code used in the above post or you can manually remove the reference to the author and date from your single.php and index.php.