What is the best way to obtain the attendance sheet when you have a free time of shifts and change in daily basis ? It's depending on the arrival time of customer?

From my point of view the best way to obtain the attendance sheet when have a free time of shifts and change in daily basis will have to do with the use of clock in and out via traditional time clocks. This will able the easy tracking of how long employees work on specific projects and creates office-wide schedules.