Conditional custom field based on time

I assume you just want help with the specifics of figuring out if the current day matches a specific date, see below..

if( '12-25-2010' == date("m-d-Y") ) {
   // It's christmas day
   // month-day-year
}
else {
   // It's any other day
}

Hope that helps..

Replace the appropriate part of the example with your custom field variable?

$your_var = get_post_meta( $post->ID, 'your_meta_key', true );
if( $your_var == date("m-d-Y") ) {
....etc..

or

$your_var = get_post_meta( $post->ID, 'your_meta_key', true );
if( '12-25-2010' == $your_var ) {
....etc..

Not sure i follow, but i assume one of the above is what you’re looking for?

Meta functions:
http://codex.wordpress.org/Custom_Fields#Function_Reference

PHP basics:
http://php.net/manual/en/control-structures.if.php
http://www.php.net/manual/en/control-structures.else.php
http://www.php.net/manual/en/language.operators.comparison.php
http://php.net/manual/en/language.operators.php