The answer will depend on where in the world and whether you are talking about legally permitted hours or the reality.
A standard work day in the US is eight hours.
A salaried worker gets paid the same wage every pay day no matter how many hours worked as opposed to an hourly worker who gets paid only for the hours worked (and gets paid overtime rates if they work more than 8 hours in a day or 40 hours in a week) or a piecework worker who gets paid per finished piece they make of acceptable quality no matter how many hours worked.
how many hours is child labor Children worked 6 days a week for 12 to 14 hours a day.
5 hours
Less then two hours a day
24
24 hours
3 hours 60 hours 60 hours
3 hours a day
2-3 hours
the average social worker work the average hours of 40 hours a week. That doesn't include the addition input hours of having to go to afternoon meetings and evening visits with their clients
There is nothing anywhere that specifies how many hours any construction worker has to do daily. Most will do 8 hours,unless the project is behind in which case they often work more hours in a day by choice.