In my case, it's not a "lab" but, rather, a suite of products that all rely on "time" (and, sometimes even time-of-day) to varying degrees -- as dictated by their end users.
E.g., in the house, I don't really care that the "(wall) clocks" tell the *correct* time(-of-day). Rather, that they record the passage of time accurately. Over very long time intervals (ironically, tolerating more short term error than long!) So, in 3523453453 seconds, each timepiece should have advanced
3523453453 seconds (within my tolerances).OTOH, when distributing audio/video, I probably want to be sure the rate at which the source material is being reproduced is relatively close to that at which it was recorded (not that my ear can discern the difference a 0.5% pitch represents). Rather, video being reproduced at one rate can loose sync with audio being reproduced at a different rate (wrt the video in terms of relative accuracy)
Different needs in a given environment.