Can I be given extra duty 14 days from being separated by the army?

Until you are out of the gate with DD-214 in hand you are subject to any discipline as necessary under UCMJ. Be smart, not a smart-ass!

Oh yes the fuck they can. Up until you have that golden ticket that is your dd214 in your hand, you keep your shit on the straight and narrow.

Had a guy in my unit that kept going UA, getting busted for weed, sleeping on duty - just being a general dirtball. The last time he was brought in for Article 15 the CO asked him what he wanted to do. Kid says he wants out to go work at a gas station (back when there were gas station attendants, not as a mechanic) in Brownsville for his uncle. The CO told me to make it happen. In the meantime the kid lost more pay, was restricted to the base and served extra duty until I was able to get him processed out. That took about two weeks. So, yes, you can get extra duty or any other punishment up until the day you are discharged.

Seems like they already did............suck it up and finish strong. Next month you will no longer care how that 2 weeks was spent.