It depends. Fission is complex. Factors include reactor design, fuel age, xenon accumulation, which parts of the RPS tripped, whatever axles the resident NRC inspector(s) wrap themselves around... those are few I can think of as a layman.
"Do they have any sort of fast recovery procedure?"
While operators do strive to minimize outage there is no general "fast recovery" procedure. There is a startup procedure and that's what you follow. If everything is optimal then 12-ish hours to begin the restart, several hours thereafter to become critical, then a relatively slow process of pulling rods until full power is achieved. "Hot xenon" startups are something you study and practice in a simulator.
The military has other prerogatives and naval reactors see rapid and frequent transients. Naval reactors are built (at great expense) to do this. They're also smaller than civilian power reactors; a 165 MWe naval reactor being thought "large" whereas a 600 MWe civilian power reactor is on the small side.
