I've never seen Dominate RP'd as literally as [MENTION=6679551]Arrowhawk[/MENTION] is describing, I'm more familiar with [MENTION=6669384]Greenfield[/MENTION]'s explaination of 'Give a command, individual then reasons the most simple/logical way to do so within limits of ability'.
However, with the reading of the Dominate spell wording, I could see how a DM could play Arrowhawk's way. I just have never seen it before.
I'm sure you haven't seen anyone play the Dominate spell in such a way. There are undoubtedly many ways to interpret how the spell works. But I'll share with you some of the Rule of the Game statements made specifically about Dominate Person:
As with the suggestion spell, it pays to be careful how you phrase orders. For example, if you order a subject to attack its ally, it almost certainly will get a saving throw to throw off the spell. The subject, however, can accomplish this order with a single action. If you repeat the order, the subject will get a new saving throw. On the other hand, if you order a subject to slay one of its allies, the subject will get only one saving throw.
It's a safe bet Greenfield would never consider that the "attack your ally" command would be completed with one swing of the sword.
The other important point of contention is some people want to impose a "to the best of your abilities" clause in with Dominate. The rule makes no such requirement. Neither does RotG talk about any such requirement. RotG does use that language with the
Command spell, but not with Dominate.
Let's look at Command in the SRD
You give the subject a single command, which it obeys to the best of its ability at its earliest opportunity. You may select from the following options.
SRD also includes that requirement with Summon Nature's Ally, but not with Dominate. So WotC clearly knows about using that phrase. For me, the fact that "to the best of its abilities" is absent, signifies a material omission to the manner in which the spell is intended to work. Like anything, a DM can always Rule 0 that requirement in there, but RAW doesn't have it.
Now, how quickly someone will attempt to go to sleep is not covered. Do they go find a bed, do they walk around until they get tired, do they lay down on the floor, would they drink a Sleeping potion if they had one handy, do they attempt to sleep standing up?...no definitive answer.