{{Start Date:STARTDATE}} to {{End Date:ENDDATE}} for all day event

Hi,

We are using custom layout for displaying events. http://gdi.stagesoho.com/index.php/en-us/events
We are displaying time as :
Date: {{Start Date:STARTDATE}} to {{End Date:ENDDATE}}

But some of our events are all day, and for these start and end time in empty.
How can we fix it? Which variable to select? so when Event have time, it will display: time, and if event is all day - it will display: all date event

Please advise,
Sandra