TL;DR: You might want to look into Sphin or some other model-checker for Hybrid Real-Time Systems.
It is possible, somehow, to design a system with a discretized clock signal
using Promela and then express some LTL property over some internal variable keeping track the flow of time. However, I did this only for small toy examples and I would not advice to use it on larger projects.
From the documentation of Promela (emphasis is mine):
In the basic Promela language there is no mechanism for expressing
properties of clocks or of time related properties or events. There
are good algorithms for integrating real-time constraints into the
model checking process, but most attention has so far been given to
real-time verification problems in hardware circuit design, rather
than the real-time verification of asynchronous software, which is the
domain of the Spin model checker.
The best known of these algorithms incur significant performance
penalties compared with untimed verification. Each clock variable
added to a model can increase the time and memory requirements of
verification by an order of magnitude. Considering that one needs at
least two or three such clock variables to define meaningful
constraints, this seems to imply, for the time being, that a real-time
capability requires at least three to four orders of magnitude more
time and memory than the verification of the same system without time
constraints.
The good news is that if a correctness property can be proven for an
untimed Promela model, it is guaranteed to preserve its correctness
under all possible real-time constraints. The result is therefore
robust, it can be obtained efficiently, and it encourages good design
practice. In concurrent software design it is usually unwise to link
logical correctness with real-time performance.
Promela is a language for specifying systems of asynchronous
processes. For the definition of such a system we abstract from the
behavior of the process scheduler and from any assumption about the
relative speed of execution of the various processes. These
assumptions are safe, and the minimal assumptions required to allow us
to construct proofs of correctness. The assumptions differ
fundamentally from those that can be made for hardware systems, which
are often driven by a single known clock, with relative speeds of
execution precisely known. What often is just and safe in hardware
verification is, therefore, not necessarily just and safe in software
verification.
Spin guarantees that all verification results remain valid independent
of where and how processes are executed, timeshared on a single CPU,
in true concurrency on a multiprocessor, or with different processes
running on CPUs of different makes and varying speeds. Two points are
worth considering in this context: first, such a guarantee can no
longer be given if real-time constraints are introduced, and secondly,
most of the existing real-time verification methods assume a true
concurrency model, which inadvertently excludes the more common method
of concurrent process execution by timesharing.
It can be hard to define realistic time bounds for an abstract
software system. Typically, little can be firmly known about the
real-time performance of an implementation. It is generally unwise to
rely on speculative information, when attempting to establish a
system's critical correctness properties.