Sorting a query by custom field date

EDIT: Reworded the question for more clarity

I’m trying to sort by custom meta box data, which I am converting to a date using the strtotime function, but I’m having some difficulty.

My chief problem seems to be a catch-22 with the strtotime function. If I use strtotime inside the loop (see below) I cannot use the UNIX time to sort by date. However, if I process the strtotime upon save (in functions.php), I run into a bunch of problems with the meta box updating / not parsing if the user edits the post or re-saves.

Is there a simple solution to this? Here is the code… I just want to order these posts in ascending order by the custom date field (not the posted date).

EDIT: Fixed the array by adding a meta-key – solution still pending

<!-- The args -->
<?php
$args = array(
    "post_type" => "podcasts",
    "meta-key" => "_date",
    "orderby" => "meta_value",
    "order" => "ASC"
    );
?>

<!-- The Query -->
<?php $podcasts = new WP_Query( $args ); ?>

<!-- The Loop -->
<?php if ( $podcasts->have_posts() ) : while ( $podcasts->have_posts() ) : $podcasts->the_post(); ?>

<!-- Convert Date to Date Stamp -->
<?php $podcast_date = get_post_meta($post->ID, '_date', true);?>
<?php $fixed_date = strtotime($podcast_date); ?>

<!-- Content -->

EDIT: Added relevant meta-box code (below) from functions.php
Note — This code does not include the strtotime function anywhere because I’m currently using it on the page template. I could include it here, but I am not sure what to do to allow the user to edit posts / resave. Once the strtotime function runs upon save, wouldn’t it change the meta-box date to something like 1327248252? If so, that won’t parse the next time that post is saved, creating issues.

// Create podcast Meta boxes

function add_podcast_metaboxes() {
add_meta_box('podcast_info', 'podcast Information', 'podcast_info', 'podcasts',  'normal', 'high');
}

// podcast Meta Box

function podcast_info() {
global $post;

// Noncename needed to verify where the data originated
echo '<input id="podcastmeta_noncename" name="podcastmeta_noncename" type="hidden" value="' .     wp_create_nonce( plugin_basename(__FILE__) ) . '" />';

// Get the data if its already been entered
$week = get_post_meta($post->ID, '_week', true);
$date = get_post_meta($post->ID, '_date', true);
$description = get_post_meta($post->ID, '_description', true);

// Echo out the field
echo '<strong>Week</strong><br /><em>What week of the series is this podcast?</em>';
echo '<input class="widefat" name="_week" type="text" value="' . $week  . '" />';
echo '<strong>Date</strong><br /><em>Enter the Date the podcast was recorded</em>';
echo '<input class="widefat" name="_date" type="text" value="' . $date  . '" />';
echo '<strong>Description</strong><br /><em>Enter the text you would like to display as a description on the media archives list.</em>';
echo '<input class="widefat" name="_description" type="text" value="' . $description  . '" />';

}

// Save the podcast Meta box Data

function save_podcast_meta($post_id, $post) {

// verify this came from the our screen and with proper authorization,
// because save_post can be triggered at other times
if ( !wp_verify_nonce( $_POST['podcastmeta_noncename'], plugin_basename(__FILE__) )) {
return $post->ID;
}

// Is the user allowed to edit the post or page?
if ( !current_user_can( 'edit_post', $post->ID ))
    return $post->ID;

// OK, we're authenticated: we need to find and save the data
// We'll put it into an array to make it easier to loop though.
$podcast_meta['_week'] = $_POST['_week']; 
$podcast_meta['_date'] = $_POST['_date'];
$podcast_meta['_thumbnail'] = $_POST['_thumbnail'];
$podcast_meta['_seriesimg'] = $_POST['_seriesimg'];
$podcast_meta['_description'] = $_POST['_description'];

// Add values of $podcast_meta as custom fields

foreach ($podcast_meta as $key => $value) { // Cycle through the $podcast_meta array!
    if( $post->post_type == 'revision' ) return; // Don't store custom data twice
    $value = implode(',', (array)$value); // If $value is an array, make it a CSV    (unlikely)
    if(get_post_meta($post->ID, $key, FALSE)) { // If the custom field already has a value
        update_post_meta($post->ID, $key, $value);
    } else { // If the custom field doesn't have a value
        add_post_meta($post->ID, $key, $value);
    }
    if(!$value) delete_post_meta($post->ID, $key); // Delete if blank
}

}
add_action('save_post', 'save_podcast_meta', 1, 2); // save the custom fields