Here are some changes to the list.php and single.php templates in order to display just one date and the time range.

list_and_single.php

<?php
/*
	////////////// SNIPPET FROM LIST.PHP
	
	In the conditional below, I removed " || !tribe_get_all_day() ".  Both of the conditionals were returning nothing, 
	so the second one ("not true") was catching my event.  My event has the same dates, but different times.   
*/
?>
<?php if (tribe_is_multiday()): ?>
<tr>
  <td class="tribe-events-event-meta-desc"><?php _e('Start:', 'tribe-events-calendar'); ?></td>
	<td class="tribe-events-event-meta-value" itemprop="startDate" content="<?php echo tribe_get_start_date(); ?>"><?php echo tribe_get_start_date(); ?></td>
</tr>
<tr>
	<td class="tribe-events-event-meta-desc"><?php _e('End:', 'tribe-events-calendar'); ?></td>
	<td class="tribe-events-event-meta-value" itemprop="endDate" content="<?php echo tribe_get_end_date(); ?>"><?php echo tribe_get_end_date(); ?></td>
</tr>
<?php else: 
/*
	Previously, this part just displayed the start date and time.  No end time.  I modified it so the first row
	shows the date, alone.  The second row shows just the start and end times, as a range of time.
*/
?>
<tr>
	<td class="tribe-events-event-meta-desc"><?php _e('Date:', 'tribe-events-calendar'); ?></td>
	<td class="tribe-events-event-meta-value" itemprop="startDate" content="<?php echo tribe_get_start_date(); ?>"><?php echo tribe_get_start_date($post->ID,false); ?></td>
</tr>
<tr>
	<td class="tribe-events-event-meta-desc">Time:</td>
	<td class="tribe-events-event-meta-value" itemprop="startDate" content="<?php echo tribe_get_start_date(); ?>"><?php echo tribe_get_start_date($post->ID,true,' ') . " - " . tribe_get_end_date($post->ID,true,' '); ?></td>
</tr>                    
<?php endif; ?>

<?php
/*
	////////////// SNIPPET FROM SINGLE.PHP
	
	In the first conditional below, it was checking to see if tribe_get_start_date() == tribe_get_end_date(). 
	Because my end time is different than my start time, these were not equal and my event was being treated as 
	a multi-day event.  So, I added the multi-day conditional here instead.
	
	In the "else" section (where I want to end up), I changed it to be like the list.php change above, so that 
	date is on one line and the time range is on the next.
*/
?>
<?php if (tribe_is_multiday()) { ?>
	<dt class="event-label event-label-start"><?php _e('Start:', 'tribe-events-calendar'); ?></dt> 
	<dd class="event-meta event-meta-start"><meta itemprop="startDate" content="<?php echo tribe_get_start_date( null, false, 'Y-m-d-h:i:s' ); ?>"/><?php echo tribe_get_start_date(); ?></dd>
	<dt class="event-label event-label-end"><?php _e('End:', 'tribe-events-calendar'); ?></dt>
	<dd class="event-meta event-meta-end"><meta itemprop="endDate" content="<?php echo tribe_get_end_date( null, false, 'Y-m-d-h:i:s' ); ?>"/><?php echo tribe_get_end_date(); ?></dd>						
<?php } else { ?>
	<dt class="event-label event-label-date"><?php _e('Date:', 'tribe-events-calendar'); ?></dt> 
	<dd class="event-meta event-meta-date"><meta itemprop="startDate" content="<?php echo tribe_get_start_date( null, false, 'Y-m-d-h:i:s' ); ?>"/><?php echo tribe_get_start_date($post->ID,false); ?></dd>
	<dt class="event-label event-label-date">Time:</dt> 
	<dd class="event-meta event-meta-date"><meta itemprop="startDate" content="<?php echo tribe_get_start_date( null, false, 'Y-m-d-h:i:s' ); ?>"/><?php echo tribe_get_start_date($post->ID,true,' ') . " - " . tribe_get_end_date($post->ID,true,' '); ?></dd>            
<?php } ?>