merge two lists + sort on date

Hi. I have two sets of calendar editors, "Events" and "Workshops" and we need to merge those listings into one merged list for display on the Home Page, but ALSO sort the final list display by 'start_date'.

What's happening with the code below is the lists are merged into one, but the records displayed in that list are split with the top of the list showing all 'events' records listed by start_date, followed by all 'workshops' listed records by start_date.

// list of events   
list($eventsRecords, $eventsMetaData) = getRecords(array(     
'tableName'   => 'events',     
'where'       => '(publish_date <= NOW()) AND (removal_date>= TIMESTAMP(CURDATE(), "00:00:00")) AND featured LIKE "1"',     
'limit'       => '3',     
'orderBy'     => "start_date ASC",             
));      

// list of workshops   
list($workshopsRecords, $workshopsMetaData) = getRecords(array(     
'tableName'   => 'workshops',     
'where'       => '(publish_date <= NOW()) AND (removal_date>= TIMESTAMP(CURDATE(), "00:00:00")) AND featured LIKE "1"',     
'limit'       => '2',     
'orderBy'     => "start_date ASC",   
));  
?>

<?php // merge two tables into one list  
$eventsandworkshopsRecords = array_merge($eventsRecords, $workshopsRecords);  
?>

In my HTML I have:

<?php foreach ($eventsandworkshopsRecords as $record): ?>
<?php echo htmlencode($record['start_date']) ?>
(...etc...)
<?php endforeach ?>

I'm hoping someone has a solution for this as it would really make my day!

Thanks for any help.

~ Deborah