Yes, at checkout there is an option to buy the game for someone else, where you'll be able to enter their impulse account email rather than your own.

I remember an old thread about gifting from a while ago, and someone's way around that was to set up a free email address (gmail or whatever), gift the game/software to that email address, and then when it came time to give the gift, give them the name+password of the email address. And if you want to go all out, you can get a box that is roughly game-box-sized, print out a picture of the boxart of the game and put it on top.

I guess he knows the e-mail, but wants the notification e-mail to be delivered at some specific day/time.