Software That Employs To Work As A Computer And/or Software Engineer For The Government/military, What Skills Are Required/prefered?

To work as a computer and/or software engineer for the government/military, what skills are required/prefered? - software that employs

US / Canadian Gov't. Or, for the United Nations, Interpol and other things. I want to work just an idea for me on my abilities, in addition to programming skills are required to. In addition, it would be a normal working day per week for a team and / or engineering software used in this institution?
Thank you in advance.