The closest (but still not good enough) would be the Time and Rate Rule which sets the time of day and the rate at which time changes. I checked it to see if it could be set to 0x (meaning time does not change) but alas the slowest it can give is normal speed (1x).
But your request does raise a question - why?
If time does not change then none of the rules or driver commands that rely on the Trainz clock reaching a set time or passing through a set time interval would work.