How much time should be spent per account?

Hey everyone, I’d like to know how much time I should be spending per client. I'm working on growing my client base and building my portfolio, and I'm charging €200/month (Europe-based). Some clients are PPC only, while others are PPC and social media. Right now, I have 8-10 clients, and I’d like to know if spending one hour per day per account is enough. Thanks in advance!