not necessarily -- client pays for 1 week of your time, you could set that week to this week or next, perhaps you're finishing a week for client A, and then goi

not necessarily -- client pays for 1 week of your time, you could set that week to this week or next, perhaps you're finishing a week for client A, and then going to work 1 week for client B. -- the benefit is you also save a lot of time (and mind fuckery) having to make detailed hourly estimates that almost never are that accurate, it's much easier to estimate a week's worth of time than it is 5-10 hours worth and be super accurate. Also bigger clients don't really throw up much fuss one way or the other, they just want good developers/freelancers.