They were released at different times everyday to allow for different schedules and timezones.
The clues were on the Pottermore website in the middle of the page. They appeared at different times throughout the seven days.
August 4, 2011
August 5, 2011
August 2nd 2011.
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The clue on day 2 was released at 9am GMT.
You have to wait until it opens in October.
Each day a new clue was released which, if answered correctly, led to one of Pottermore's partner websites. The quill would be hidden somewhere on the main page of that website.
There was no separate website for Pottermore beta testing. To access it you had to successfully complete the Magic Quill Challenge. The site is now open to all.
You are no longer able to find the magical quill, as the challenge has ended. You had to answer the question correctly in order to find the quill.
The Clue for Day Five was: What is the house number of the Headquarters for the Order of the Phoenix in Grimmauld Place?
Question: How many Deathly Hallows are there? Multiply this number by 7 Answer: 3 x 7 = 21