It is not permissible to delay the prayer beyond its time because of work as work is not an excuse for delaying prayer. Zuhr and ‘Asr and Maghrib and ‘Isha prayers are the ones that can be combined (in some cases). But you cannot join `Asr and Maghrib. So you must organize your time at work in a way that will not interfere with your performing the prayers on time.

The times when prayer is forbidden are three: 1- From when dawn breaks until approximately a quarter of an hour after the sun has risen. 2- Approximately a quarter of an hour before the time for Zuhr prayer begins, until the time for Zuhr begins. 3- After you have prayed `Asr until the disk of the sun has set completely.

If a woman’s period starts after the time for Dhuhr has begun and enough time passed to pray at least one Rak`ah, then she must make up that prayer after becoming pure.