Return events that take place on date based on list of events with date ranges

If I understand correctly then the following array entered formula displays what you want:

Formula:

=IFERROR(INDEX('Form responses '!$A$2:$A$4,SMALL(IF(('Form responses '!$C$2:$C$4<=$A2)*('Form responses '!$D$2:$D$4>=$A2)*('Form responses '!$F$1:$L$1=TEXT($A2,"dddd"))*('Form responses '!$F$2:$L$4=""),ROW('Form responses '!$A$2:$A$4)-ROW(INDEX('Form responses '!$A$2:$A$4,1,1))+1),COLUMN(A:A))),"")

Note that only non event days are identified on the Form Responses sheet.
I am not sure how this translates into Google Docs, I would suspect that placing the ArrayFormula function in front would work.
Let us know if you have any questions.