My nature of job is of supporting machines at a Departmental Store. The person on duty is to carry the company's hand phone. There is also a Mosque which is only a five minutes walk. Performing daily prayers is no problem for me. Cashier machines, etc. need to be supported when there is any technical or other breakdown. Some problems can be solved by hand phone, the rest need to be attended personally.
My question is if there no problem at sales floor can I do my daily prayers in Jama'ah (congregation) rather than wasting my time in the office at Salat times. Are my prayers accepted? Is it Halal or Haram to do my prayers during my working time? I am doing it in congregation and if there is any problem I quickly attend to it either in conversation or physically in person. I do at times sacrifice my meal times also for my job.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Observing the prayer in congregation is an individual obligation on every Muslim, who is adult, hears the call to prayer, and does not have any Sharee’ah approved necessity that prevents him from attending the congregational prayers in the Masjid.

There are many authentic evidences in this regard. Therefore, dear brother, it is incumbent on you to attend the congregational prayer if the Masjid is so close to you that you can hear the call to prayer in normal circumstances, even if you are a technician whose duty demands permanent attendance. However, if there is a real proof that your going to the Masjid can bring harm upon the work you are employed to do, you can then not attend the congregational prayer in the Masjid, because, the fear over property is a valid excuse in the Sharee’ah. But you should not delay the prayer until its time expires.

Allah knows best.