How much of the timing on samples is down to lab availability, though? E.g. my gp wants samples in by 1pm because otherwise they'll got to the lab the following

How much of the timing on samples is down to lab availability, though? E.g. my gp wants samples in by 1pm because otherwise they'll got to the lab the following day. If the lab would still process things that came in at the end of the day, I could very much see larger doctors offices sending off samples more than once a day, with the last one coming in after the end of their clinics. I could see demand spreading out more - though I agree it might be closer to 2 than 4 - if the availability of human labor wasn't an issue.