You are mistaken. First of all, military troops routinely work on weekends. All those men and women deployed work 24/7 their whole deployment. There are no "days off." My husband's last deployment was 10 months. In that 10 months, he got exactly one 24 hour period "off" because he had a 103 fever and was quarantined to his bed. He worked ever single day otherwise. There are currently thousands of deployed troops working right now, in addition to the thousands more stateside who are required to work on weekends.
Second, the military has not been funded past Jan 19. They are currently working without pay, although they will eventually be paid for these days. BUT, the next paycheck due to come Feb 1 was supposed to cover Jan 16-31. There will be NO paycheck coming on the 1st of February for any military active duty. They cannot be paid without funding, and the contractor that processes the military payroll will not be doing any work until a budget is passed or a bill to find the military without disruption to pay is passed. They have technically been paid for 4 work days out of the 15 day work cycle. However, as I mentioned, there is no one to process that payroll, so there won't be a check coming on the 1st for even those 4 days.
FWIW, my information comes from the official government notice sent out to my husband's work email address (he is responsible for passing this information along to his Marines) from the Department of Defense and signed by General Mattis (Secretary of Defense). It was dated yesterday, Jan 20.