1 day and 10 hours, according to Puella Wiki. Sounds kinda weird to me, since by my timezone it means the broadcast should start around 10 PM despite being promised in "the usual timeslot". Come on, by 10 PM I used to read tons of spoilers at AS already! Then again, it's JST, and I don't quite understand how it correlates...
My workday will finish at half past eight (18.30 GMT) and I consider marching towards an internet cafe right away. Maybe the overall hype will make a miracle happen, and we'll get subs that soon. If not, I might just try watching it online anyway...
Shaft placed a full page ad in a big time Japanese newspaper. Such ads are said to cost a fortune!
There are also collected ending speculations. The real ending is just around the corner. Also, someone from the staff tweeted that the studio kept fixing and polishing the episodes until last weekend.
Btw, here's a [harsh] moment that I still would love to see in the ending. Except that won't happen.