Should employees record start and stop times of the day?
Sure, if that information is of value. In some organizations, knowing the start and end times of the day is critical to business processes such as payroll. Sometimes people are paid different amounts based on what time of day they did their work. In other situations, it may be very important to know that a task was completed at night instead of during the day so certain inspection procedures are updated.
However, if the data won't ever be used for something valuable, then there's no reason to collect it. A practice that we've seen from time to time is an organization that tries to reconcile the arrival and departure of staff with the totals on their timesheet. It's certainly possible to do, but we wonder "What will you do with the information?" Often the answer to that is not at all clear.
Make sure you've got an idea of what your return will be from the investment of time entering data by all the staff.