Here's one if you need anymore

=AND(OR(IF(Start2<End1;"True";"False");IF(Start2=E nd1;"True";"False"));OR(IF(Start1<End2;"True";"Fal se");IF(Start1=End2;"True";"False")))

It looks weird but all it does is compare the end dates to the start dates
and if one of them is larger then they intersect.