Sure it is!
Just go to the calendarscript/templates/admin/English directory and find the file add_edit_event.html . Then go almost to the bottom until you see a long line of <input type="hidden"> tags. Add one more that says:
<INPUT TYPE="hidden" NAME="SCHEDULE_all_day" VALUE="1">
The next thing below all those hidden input's is a <table> tag, followed by two short (5 and 3 lines) <tr> ... </tr> tags. The next (long - I counted 31 lines) <tr> ... </tr> tag is the part you need to either delete or comment out with <!-- and -->. Do that, and you should have a time-free scheduling page.
Enjoy!
David
------------------
David Whittaker
http://www.uabcm.com/
http://www.csworkbench.com/