Are those who are appointed to guard important places excused for not praying Jumu’ah?
Question

I am a man working in the military. I am often asked by soldiers and others who are appointed to guard places (which may be sensitive) and they may be rebuked or disciplined if they abandon their posts. Are they excused from attending Jumu’ah and can they pray Zuhr instead? What is the ruling if the mosque is close to them?.
Praise be to Allah.The one who is appointed to guard some important places is excused for staying away from Jumu’ah, even if the mosque is close by, and he may pray Zuhr instead, but in this case the smallest number of guards that will suffice should be appointed, because Jumu’ah is very important and it is not permissible to neglect it. 
The Standing Committee for Issuing Fatwas, under the leadership of Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him) was asked about telegraph and telephone facilities which are in constant use throughout the week, including Friday, and there are employees who supervise the phone systems and wireless systems and their work does not allow them to leave, even for a minute, because that may cause a breakdown in the wireless and telephone systems. Can these employees leave their work and go to pray? 
They replied: 
The basic principle is that Jumu’ah is obligatory for all individuals, because Allah says (interpretation of the meaning): 
“O you who believe (Muslims)! When the call is proclaimed for the Salaah (prayer) on Friday (Jumu‘ah prayer), come to the remembrance of Allah [Jumu‘ah religious talk (Khutbah) and Salaah (prayer)] and leave off business (and every other thing). That is better for you if you did but know!” [al-Jumu’ah 63:9]
And Ahmad and Muslim narrated from Ibn Mas’ood (may Allah be pleased with him) that the Prophet (peace and blessings of Allah be upon him) said concerning some people who stayed away from Jumu’ah prayer: “I was thinking of telling a man to lead the people in prayer, then I would burn down the houses of men who stayed away from Jumu’ah.”  
And Muslim narrated from Abu Hurayrah and Ibn ‘Umar (may Allah be pleased with them) that they heard the Messenger of Allah (peace and blessings of Allah be upon him) say from his minbar: “People should stop staying away from prayers in congregation or else Allah will put a seal on their hearts, then they will be among the heedless.”  
And the scholars are unanimously agreed on that. But if there is a legitimate shar’i excuse for one who is obliged to pray Jumu’ah, such as if he is directly responsible for work that has to do with national security or protecting national interests, which requires him to do that work at the time of Jumu’ah prayer, such as those who are in charge of security, traffic, and wireless and telephone communications, etc, who are in charge at the time of the second call to Jumu’ah prayer or  when the iqaamah is given for prayer in congregation, then they and others like them are excused for not praying Jumu’ah or offering prayers in congregation, because Allah says (interpretation of the meaning): 
“So keep your duty to Allah and fear Him as much as you can”
[al-Taghaabun 64:16].
And the Messenger of Allah (peace and blessings of Allah be upon him) said: “Whatever I forbid to you, avoid it, and whatever I enjoin upon you, do as much of it as you can.”  
And it is no less an excuse than that of the one who is excused because he fears for himself or his property, etc., who the scholars said is excused for not attending Jumu’ah or prayers in congregation, so long as the excuse is there. But that does not mean that the obligation to pray Zuhr is waived, rather he must pray Zuhr on time, and if he is able to offer it in congregation then he must do so, as with the other five daily obligatory prayers. End quote. 
Fatawa al-Lajnah al-Daa’imah (8/188). 
They were also asked about the owner of a gas station that is approximately two kilometres away from the city. Is it permissible for him to appoint someone to guard the gas station at the time of Jumu’ah prayer to protect it against arson and theft, and is Jumu’ah prayer waived for the guard and can he pray Zuhr instead – knowing that the gas station has been set on fire and the store robbed before that? The owner of the gas station lives there with his children and family, and the guard also lives there with his children and womenfolk. 
They replied: If the situation is as described, it is permissible for the guard to pray Zuhr instead of Jumu’ah, so that he may guard the people and property mentioned, because of the general meaning of the evidence which indicates that one may be excused from praying Jumu’ah in such cases. End quote. 
Fatawa al-Lajnah al-Daa’imah (8/192). 
And Allah knows best.