My first salaried job was as a salesman; we incurred expenses, which we could claim back. It was explained to us that the system was there to ensure that we weren't out-of-pocket; claims didn't have to actually be true, but you did have to have incurred the expense.
I fairly soon realised that this was a lie; the expenses system was really a salary-augmentation scheme, and you were expected to inflate your claims. Everyone was at it.
I have CO2 monitor, which I use to estimate is my brain working or not: when I'm working, CO2 level raises quickly above 1000ppm, so I need to ventilate my room often; when I'm idling, e.g. by playing a simple game, CO2 level is at about 740-790ppm without ventilation for whole day.
When I'm returning from work, I see at CO2 monitor that my head is still working. Yes, I'm able to «work» sustainable 4h per day only, but «work related activity» consumes my brain for whole day.
Does this track w/ respiration rate or heart rate?
I've never thought about this - it seems like it would be hard to measure w/o a more intense face mask vo2 max testing type setup.
An hour long meeting booked, that ended up taking 45mins? It's an hour. It's the same reason we don't expect you to stop recording time when you to down the hall to make a coffee or take a bathroom break. The numbers only really makes sense at the aggregate level, and going to a higher level of detail is not reliable because of all the noise and different ways people measure their time.