Prayer: If I do personal work after office hours during a work trip, should I pray full or qasr and fast or not?

Practical Laws of Islam as per the teachings of Imam Khamenei

Prayer: If I do personal work after office hours during a work trip, should I pray full or qasr and fast or not?

English:

Question #644:

If I do certain personal work at my place of work after the time of my official assignment for which I have traveled (for example, I do my office work from 7 a.m. till 2 p.m. and do personal work after 2 p.m.), what will be the rule of my prayer and fasting?

Answer #644:

Doing personal work during travel for official assignment, after completing the office work, does not change the rule of travel for official assignment.

-Imam Khamenei, Practical Laws of Islam, Importance and Conditions of Prayer