Bottom Line
No! The punishment must run consecutively. It cannot be broken up into weekends and week days. Please see the reference below.
Discussion
AR 27-10 3-19(8) Combination and apportionment. With the following exception, punishment authorized under UCMJ, Art. 15(b) may be combined: No two or more punishments involving deprivation of liberty may be combined, in the same nonjudicial punishment proceedings, to run either consecutively or concurrently, except that restriction and extra duty may be combined in any manner to run for a period not exceeding the maximum duration that can be imposed for extra duty, by the imposing commander. Once commenced, deprivation of liberty punishments will run continuously, except where temporarily interrupted due to the fault of the Soldier, or the Soldier is physically incapacitated, or an appeal is not acted on as prescribed in paragraph 3–21b. (See para 3–21c, below regarding the circumstances when deprivation of liberty punishments, imposed in separate nonjudicial punishment proceedings may run consecutively.)
Punishment must run concurrent and from the day it starts it will run 14 days and cannot be interruptions still count unless it is the Soldier’s fault?
The Commander may think he is doing you a favor or helping you out. You might try approaching him in a professional manner and showing him the regulation. If that does not work then take it up the Chain of Command to the BN CSM/CDR or consider taking the issue to the IG.