Hi, thanks for using out plugin and I can help you get in the right direction.
There are a couple ways you can do this.
Template Method
You can follow the Themer’s Guide and move the month/content.php to your theme and write under the this function:
<?php tribe_get_template_part( 'month/nav' ); ?>
The text you would like.
Hook Method
I came up with this function you could place in your theme’s functions.php to do the same.
add_action( 'tribe_events_after_header', 'ecp_under_title_function' );
function ecp_under_title_function( $query ) {
if (tribe_is_month()) {
echo " Double click on event to see details and entry forms when available";
}
}
That should be enough to get you started you may have to style that by adding some tags and css.
Let me know if that works for you.
Thanks