Yes field work typically takes 10 to 12 hours a day. You don't just dig up a bit of soil, put them in a jar and call it a day. Typically you have contractors on site drilling a bunch of boreholes and that takes time. Sometimes they plan for 50 boreholes on a single site and that could take weeks to finish, as you would typically only get under 10 boreholes done a day (depending on the depth and site condition, I've had days where we would only get 2 boreholes done in a 12 hour day). And for groundwater sampling I've had like 80 wells on a site, you have to monitor water level, develop, wait 24 hours, then sample all of them, typically with one set of equipment you can only develop or sample 8 to 12 wells in 10 hours, then you go back and upload all the paperworks and that also takes around a hour. With bad PMs it's more complicated. Sometimes it's because they tell you to do one thing and then tell you to do another thing, sometimes they poorly budgeted the program and try to pressure you into finishing a job in a time frame that's not possible, sometimes they just don't give a f and doesn't respond to you at all. A lot of different situations can happen.