Let's face it, your practice, my practice, everyone's practices, are going global. Twenty years ago, when the practice of law first began to grow out of the "single-time-zone" mentality, we could incorporate the additional burdens on our time by simply sleeping a little less here and there and then making it up as possible.
As practices now routinely cross the four most popular US timezones daily and more often than not include regular forays across the dreaded international-date-line, we simply cannot as a profession continue to burn the candle in the middle as well as at both ends.
In short, I think we need to revisit the old adage: "early to bed, early to rise." I will waste no ink reiterating the nauseatingly repeated negative consequences of a 24/7 lifestyle. Suffice it to say that we cannot function well long-term on four hours of sleep, and that on an irregular basis. To those partners who routinely have no internal body-clock left to speak of, I can only say: you are a walking timebomb. Please, please give up the "machismo" of pretending this is not costing you your health (eventually) and, more importantly for your clients and your partners, your judgment.
I'm sure I don't need to also prove that lack of regular sleep will do a number on your synapses. Do I really need to dig up hyper-links to prove that one? Let's face it, there is enough work for all of us to fill 48 hours a day, every day, for the rest of our lives. And, no, you are NOT allowed to try to do that.
We were mammals long before we were homo "sapiens, sapiens." Let's start acting like the latter (the sapiens part!) and get back to a more sane approach to living. Figure out a time of day that is most productive for you and decide to make that your "day". Figure out what time of day is "down" for you, and call it "night." Then, stick to it. Yes. You really, really, really will get more done. And, let's face it, delegation of work, and intelligent delegation, is the secret to true leadership success.
My new mantra: "healthy, wealthy and wise."