The Heisenberg uncertainty principle applies only to operators satisfying canonical commutation rules. This is the case for corresponding components of position and momentum operators, but not for the energy operator (Hamiltonian), which has no associated conjugate partner.
(Conjugate pairs of selfadjoint operators necessarily have unbounded spectrum, while a good Hamiltonian must be bounded below. This argument is due to
Die allgemeinen Prinzipien der Wellenmechanik,
Handbuch der Physik (S. Flügge, ed.), Vol V/1, p. 60,
Springer, Berlin 1958.
The general principles of quantum mechanics, p. 63,
Springer, Berlin 1980.
Time measurements do not need a time operator, but are captured well
by a positive operator-valued measure (POVM) for the time
observable modeling properties of the measuring clock.
The problem of extending Hamiltonian mechanics to include a time
operator, and to interpret a time-energy uncertainty relation, first
posited (without clear formal discussion) in the early days of quantum
mechanics, has a large associated literature; a survey article by
carefully reviews the literature up to the year 2000. (The book in which Busch's survey appeared discusses related topics.) There is no natural operator solution in a Hilbert space
setting, as shown by Pauli's argument mentioned above.
However, a well-defined time-energy uncertainty relation resembling that of Heisenberg has been rigorously established in the context of statistical mechanics by Gilmore, see
All this has nothing at all to do with any short-time creation of energy from the vacuum. The latter is a popular misinterpretation of this relation. See the discussion in Creation of particle anti-particle pairs.