3 days on the trail ending at Whitney Portal, eh. Horseshoe Meadow to Whitney Portal can be done in 3 days, if you keep your pack light and if you can do a couple of big days. The problem will be sleeping at 11,700 at or near Guitar Lake.
Diamox is a fun drug. It works perfectly for some, partially for others and not at all for a few. I fall into the partial category. I still have a fitful night's sleep and a loss of appetite at 14,000' and after big days...sometimes.
I do not take Diamox day hiking in the locals. I don't have any problems to speak of during trips of this nature.
