This excellent article confirms what I’ve always thought (and dispels my guilt too), that a sleep in the middle of the day is good for you. I’m an expert. I can sleep for 10 minutes and feel rejuvenated. I can sleep for an hour and make up for a ropey kip the night before. I always feel great when I wake up. If I feel that deadly sleepiness on a long car journey I can pull in, set my mobile alarm for 20 minutes, be asleep in seconds and wake up ready for a few more hours of driving devoid of the dreaded drooping eyelids syndrome. Don’t forget to turn off your lights though. I did that recently - parked up and forgot to turn the headlights off (it was daytime but I’d had them on to drive through a thunderstorm). Had to call out the AA to get me started. 
Even if I’ve slept well the night before, if I sit down to read at around two in the afternoon I can nod off and hardly anything will stop me. Sleeping during the day has no bearing on whether I will or won’t get a good night’s sleep that night. 
Limit your nap to 45 minutes or less, if you need to spring into action after dozing. Otherwise, you may drift into slow-wave sleep. Waking from this stage results in sleep inertia, that grogginess and disorientation that can last for half an hour or more.
ah yes…my usual problem.
Still, I’m with Steve on this. Naps can be a fine thing. On a typical day I may be up by 5:15 am, and without a short nap I’m ready to poop out by 8:30, which isn’t usually convenient.
More tea.
I can easily drop off without a moment’s noti… 
djm
i agree whole-heartedly,… but it’s getting off the computer to do so that I can’t seem to master.
-I can drop off easily for a few winks anytime. I wouldn’t call it a skill, but its a handy thing , developed in youth on endless Greyhound bus trips. Brainiac sweetie is envious as she can’t snooze at will. She was asked before birth to choose between brains or the ability to snooze at will and opted for brains. -Its my good luck as one of us has to stay awake & think.
Hah! Emm, you might want to check your typing. I know it sounds mad, but you said you’re up by 5.15… 
Obviously an error. No sane person is up before 7am. In fact there is no time before 7am. That’s when time starts - and it’s too early IMO.
Back when my then-girlfriend moved to Guam (15 hours ahead), I used to go to bed at 8 or 9 and get up at 2 or 3AM to talk to her. I loved it but it wasn’t very good for me. I get up around 7 right now but I should be getting up more like 5 or 6.