I recently set it mark a week long holiday, so it's perfectly possible.

Next to the start and end time field there is a chain link icon, so that if you advance one, the other tracks it by the default event duration. Click the tiny button to allow you to set the start and finish times (and dates) separately.

Thanks Zenos for your advice but still have the problem. I entered a date in the State Date, say 9/1/18, but when I enter a finish date, say 9/10/18, the start date of 9/1/18 automatically changes to 9/10/18. Whatever date I enter in either the Start or Finish box changes the other date. It is like a 'default problem. Any other ideas? Thanks

I simply cannot replicate your problem.

Here's a screenshot of mine. Can you see any differences with yours?

Sorry did not receive your screen shot. Up until 2 weeks ago I was able to enter a multi day event. Starting 2 weeks when I enter Oct 2 in the Start Day and than enter Oct 5 in the End Date, the Start Date changes from Oct 2 to Oct 5. In other words the Start and End Dates are the same date. Even when I enter the End Date first, the Start Date becomes whatever date I entered for End Date. Could the program become corrupted? Thanks.