aquot;[t]he appellant has the burden of proof, by a preponderance of the evidence, on the issue of timeliness. ... Department of the Interior SF-0752-09-0799-I-1 U.S. Merit Systems Protection Board May 18, 2010 43.055] Waiver, Last Chance ... appellant. a senior law enforcement ranger. ... The policy that was violated provided that art employeea#39;s failure to wear a seat belt aquot;may result in disciplinary action, aquot;anbsp;...