Adding last modified date/time to footer

Hello,

I’m attempting to add the last modified date/time to the footer of my custom theme. I found the function <?php get_lastpostmodified( $timezone ) ?> but I can’t figure out how to get it to actually write the date/time. I’m assuming there is some other function that needs to wrap this one or something.

I did some searching, but the only things in the forum were telling people to use a plugin that generates a footer, but that obviously won’t work in this case.

Anyone done this in their theme?