The yields are absolutely annualized. Not sure why you would think otherwise. I've never heard of a bond yield of any duration listed at anything other than a 12 month rate.

To find out what you would get for a 30 day, type in the yield of 4.382 and divide by 12. You get a 0.365 return. So for a $1000 purchase, you get about $1003.65 after it matures in 1 month.