Adding all day events using applescript to ical

Hey all. I am new to using applescript. Thanks to some top users i have been able to get excel events file transfered into ical.

I need help with the applescript for changing these events from time duration to all day.

tried
set the start time to 00:00 and end time to 24:00 and
set all-day to true

any help would be greatly appreciated!!
thanks.