  We formalize the concept of the modular energy operator within the Page and
Wooters timeless framework. As a result, this operator is elevated to the same
status as the more studied modular operators of position and momentum. In
analogy with dynamical nonlocality in space associated with the modular
momentum, we introduce and analyze the nonlocality in time associated with the
modular energy operator. Some applications of our formalization are provided
through illustrative examples.
