How can one estimate the minutes late for work or the minutes spent outside during working hours in order to purify the money earned, knowing that the employment period is four years and the working hours are eight hours daily?

The employee who has been negligent in his work by being late and leaving without a valid reason must return a portion of his salary corresponding to the times he was absent to his employer. If that is not possible, he should donate it to the poor and for the benefit of Muslims. If he does not know the exact amount of time, he must strive to estimate it to the best of his knowledge, such that he feels acquitted of his responsibility, along with sincere repentance.