that's just for the 15th. We got paid through today (or yesterday for me, as it's 1:37 am April 9th here). If the government is still shutdown May 1st, you're not getting paid at all. Same goes for May 15 and all pay days after April 15 in which the government is shut down.
Edit: as I stated above though, you will get backpay once the govt starts back up again for all pay that was missed.
I know someone in the Navy nuclear program in DC. They get a living stipend and what not because it's ridiculous there. I couldn't imagine having to pay DC rent without income.