Most Christians have far too few unsaved friends. Such friendships are the ideal context in which to share Christ. But deciding how much time to spend with unsaved friends depends on why you want to be with them in the first place, and how you use your time together.
For example, Samuel confronted the Israelites about their desire for a king. Having a king wasn’t wrong in itself. What was wrong were the people’s “motives” for why they insisted on a king! They wanted a king so Israel would “be like all the nations. In other words, they wanted to “be like everybody else!” Now that’s a problem!
How much time should you spend with unsaved friends? Half your time? More? Why?
Examine yourself before God does! He knows why you’re set among people! Act accordingly and according to His purpose, not yours.