If you're serious about this, you can get to below 13% by your deadline. Health concerns not withstanding, you should be able to get to less than 10% body fat.
You may want to consider something along the lines of the velocity diet. This may not be necessary at first but as you get a lower BF%, it becomes harder to lose. As such, you may want to consider a diet similar to this within ~30 days of your final measuring.
Velocity Diet