We describe a procedure to create entangled history states and measurements that would enable one to check for temporal entanglement. The checks take the form of inequalities among observable quantities. They are similar in spirit, but different in detail, to Bell tests for ordinary entanglement.
@article{arxiv.1503.06458,
title = {Bell Tests for Histories},
author = {Jodan Cotler and Frank Wilczek},
journal= {arXiv preprint arXiv:1503.06458},
year = {2015}
}