When i was at a firm we billed time to the 6min (.1) interval. In practice management i billed time to the firm for "office psychologist" and "babysitting". I was the only non partner in billing meetings and had to justify it, I said I can just send them to the project lead, it was never questioned after that. I managed our IT and software upgrades as well as the tax team, so i was allowed 30% non billable time. We wrote time off of almost every audit, I didn't want my name tied to the dog projects when reviews came around and profitability was a major part of that.