What are the dates of the days of the dead in the christian tradition?

There's no such thing.

Dias de los Muertos is a Mexican tradition, not a particularly "Christian" one. It's usually celebrated on October 31, November 1, and November 2 (corresponding to the semi-Christian holidays of All Hallows Eve, All Saints' Day, and All Souls' Day).

The reason for saying that none of these are truly "Christian" is that there's no mention of them at all in The Bible itself, and instead have their roots in pagan traditions that were co-opted by Christians, because "hey, join our religion, we don't have any parties" is not a big selling point for most people. So if your rivals are holding a party, you'd better have one around the same time too. (Similarly, the Biblical accounts of Christ's birth are hard to reconcile with a date in December; the traditional date for Christmas was probably chosen for its proximity to the winter solstice, which was another pretty popular time for pagan celebrations.)

Even more bizarre is the tendency of a lot of (mostly Protestant) churches to decry Halloween as a pagan holiday, but instead hold a "harvest festival", which is basically what the original pagan holiday that Halloween supplanted was.