Can we deduce the air date for Sherlock series four from this hint?

Sherlock series two and three were both broadcast in January. So was the Sherlock special. Filming on season four, meanwhile, is due to begin this spring. Let's be honest, the idea that the new series might be with us in January 2017 is not blowing anyone's mind, but it's still nice to have another piece of evidence that backs it up (after all, no seasoned Sherlock fan would ever dare hope it might be sooner, would they?)

This particular clue comes from Stateside, and specifically PBS, who broadcast Sherlock over there.