Can iCal

I have Snow Leopard & Lion on an older Mac, but have now gotten a newer Mac that came with Yosemite. I've moved several apps from on or another of those two OS's to Yosemite, and been pleased with how that went. But, I have iCal & AddressBook on Snow Leopard that I've moved over to Yosemite, but not successfully. I've tried dragging the snow leopard onto the Yosemite version, and U've simply tried opening the Snow Leopard, to be told "You can’t use this version of the application “iCal” with this version of OS X." So, is the answer that I just have to start again from square one with the Yosemite version?