Take two...
Added this in the head, but I don't understand why I need to do this...
<?php date_default_timezone_set('Europe/London'); ?>
What happens if someone visits the page who isn't in the Europe/London timezone?
Then I changed my date display code to the following...
<?php if (date("j F Y G:m:s",strtotime($rsCONFIRMEVENT->getColumnVal("DGCRCeventEND"))) < date("j F Y G:m:s")) { ?>
<h6><?php
echo($rsCONFIRMEVENT->getColumnVal("DGCRCeventSTART")?date("j F Y",strtotime($rsCONFIRMEVENT->getColumnVal("DGCRCeventSTART"))):"");
?></h6>
<?php } ?>
<?php if (date("j F Y G:m:s",strtotime($rsCONFIRMEVENT->getColumnVal("DGCRCeventEND"))) > date("j F Y G:m:s")) { ?>
<h6><?php
echo($rsCONFIRMEVENT->getColumnVal("DGCRCeventSTART")?date("j F",strtotime($rsCONFIRMEVENT->getColumnVal("DGCRCeventSTART"))):"");
?> - <?php
echo($rsCONFIRMEVENT->getColumnVal("DGCRCeventEND")?date("j F Y",strtotime($rsCONFIRMEVENT->getColumnVal("DGCRCeventEND"))):"");
?></h6>
<?php } ?>
...which works.
I thank me.
NJ