Congratulations on the recent 04.00.01 upgrade!  While using the Edit Event page, I noticed some JavaScript behaviors from the earlier version that could be improved upon:

1) When I select or enter an End Date, then click the "calendar" icon to select a Start Date, the End Date is automatically changed to match the currently-displayed start date.  Suggestion: The dates should automatically change themselves ONLY if Start Date is later than End Date; otherwise, there should be no change.

2) A similar situation exists with the drop-down selectors for Start Time and End Time.  If I select a value for Start Time, the End Time value automatically changes to the next time in the sequence, usually a half-hour later.  If I then change End Time to some later time, and then change Start Time again, the End Time will once again automatically adjust to a half-hour later, forcing me to reset it.  Suggestion: Start Time and End Time should adjust themselves only if a change would leave Start Date/Time later than End Date/Time; otherwise there should be no change.  If an event spans multiple days, then changing Start Time should have no effect on End Time, and vice-versa.