Masters Degree By This Time Next Year, How Feasible ?

I have a degree in computer science , and will love to have a masters degree around this time next year , the main challenge is that  Im working so I cant do it full time . Staff appraisal as been scheduled for August next year and I will have an edge with the Masters degree. I dont know of any school in Nigeria currently selling masters forms and if its possible I run it in Lagos ,  any suggestions  
Thanks .