Is DCounter a count of how many items are in the deque? Why not deque::size() ? If it is, then this:
Code:
Date[(DCounter) + i]
Is out of range.
Some suggestions:
Do you have "Jobs" that consist of a date, name, and description? Why not then keep
one deque that contains a structure that holds date/name/description triples?
Also, is a deque the right container to use? Why not use a sorted container, like set, map, multimap, etc, if you want things to always be sorted? Or, if you want a deque, why not use std::sort() ?
Data also seems a poor name for a class. There's also not much point in your destructor - the deques will correctly destruct here.