In the limits of the city of Pittsburgh, trash is included with city taxes. The day will depend on the city, and every neighborhood may have a different day of the week. I and you are responsible for taking out your own trash. You should do this after 9PM on the night before and at latest before 6AM on the day of collection. The city recycles, and therefore encourage the city residents to recycle as well. You would be doing the environmentally right thing to recycle.