“ ‘He must work with all his energy, as the righteous Yaakov said: ‘I worked for your father with all my energy.’ Therefore, he received reward [for] this also in this world, as it says: ‘The man was very, very prosperous.’ ”
Rabbi Dayan concluded: “The employer pays the employee for the time and effort he invests in his work. Therefore, when an employee wastes time or works inefficiently, he is taking wages unfairly and cheating the employer.
“Getting back to davening, the answer to your questions depends on what is customary in that time and place. In many places it is customary to allow workers a short break during the course of the day to daven Minchah. Whether this counts as the lunch break varies from locale to locale and from work to work. On the other hand, it is almost never accepted to daven Shacharis after clocking in, and you would need explicit permission from your manager.”