Special courts-martial have jurisdiction to try any person subject to this code for any offense punishable under this code. A special court-martial has the same powers of punishment as a general court-martial; except that confinement may not be more than ninety days and the fine or forfeiture of pay and allowances imposed by a special court-martial may not be more than the maximum pay and allowances received for six unit training assemblies or six days of annual training, whichever is applicable according to duty status.