Conceptualizing this, you need at least two tables, one for shifts and one for employees. In your shifts table you have your shift start/shift end fields and then you add a formula field using DATETIME_DIFF() to calculate the difference between the two (probably in minutes as it only returns whole integers). You could add another formula or write on top to format the minutes into partial hours.
Then you add a rollup field in your employee table summing the hours value, and you can add a date filter inside that field. This format gives you at a glance views of hours totals. If you're desiring longer term record keeping, a third table for pay period may be necessary.
