  An accessibility graph of a network contains a link, wherever there is a path
of arbitrary length between two nodes. We generalize the concept of
accessibility to temporal networks. Building an accessibility graph by
consecutively adding paths of growing length (unfolding), we obtain information
about the distribution of shortest path durations and characteristic
time-scales in temporal networks. Moreover, we define causal fidelity to
measure the goodness of their static representation. The practicability of our
proposed methods is demonstrated for three examples: networks of social
contacts, livestock trade and sexual contacts.
