It's whatever they damn well feel like. Back in 1943, Boozerford set the minimum limit at 175 hours (with minimum limits of return visits and studies) for special pious-sneers, 150 hours and as many studies as could be developed for regular pious-sneers (no auxiliary pious-sneers in those days), and 60 hours, a dozen return visits, and one study for everyone else. And some hounders use those numbers, or even higher ones.
And if they are trying to bust you up with a potential mate, they can use any number they damn well please. You could be getting in 250 hours of field circus a month, getting in 60 return visits, and have a dozen people attending the boasting sessions on your account, and they could still use that "he's not spiritual enough" excuse. Then, that hounder (or group of hounders) doing that could be getting in a lousy 2 or 3 hours a month and zero return visits, and still remain hounders. Those hounders can even carry on molesting children with the aim of ruining their lives, and still decide "you are not spiritual enough" for your would-be spouse. Let them hear from the hounder-hounder that they are doing this, and they will get you on "slander" charges or find a way to do a "brazen conduct" hearing on something like wearing a colored dress shirt or having a LED flashlight or LED light bulbs to save energy or for emergencies.