The reason for two year skip in the past?

In 12 Monkeys (TV series) the "meet me in two years" serves as major part of initial plot set up. At first I thought Cole is stuck jumping in intervals or something. But later it's clear that it's relaxed (relatively :) go to the past, return to the future to hang around, go to the different time.

Did I miss something (it's time travel, it's confusing, ok) or there wasn't really a reason named for doing that two–part trip with two–year gap?