many "crossing" (overlap) dDate´s

if i have a LOT of data like :

dBegin := 01.07.04 and dEnd := 15.07.04
dBegin := 10.07.04 and dEnd := 20.07.04

than the dEnd from data1 will "cross" dBegin from data2
is there a "mathematic method to calculate" this ?
( i do not mean IF(data1->dEnd > data2->dBegin,...,...)  while a LOT )

greetings by OHR
Jimmy