Does private schools have authority to cut employee's salary

I am working in a private school. The school was closed from Dec.1 to Dec 13 due to the recent floods and as my residence area was badly affected I left for my native and couldn't join back on the day of reopening. The school authorities took it as a sandwich holiday wherein the employee has to sign on the preceding and after the day of holidays on failing which the entire holiday's 50% salary will be deducted. My question is whether there is any legal support for their argument or the government has given the schools the discretion to take up a decision on such matters?