AcessDenied Trying to acess s3 bucket from url

Im using a link that I concatenate with datetime variable:

t = time.localtime(time.time())
    datetime = str(t.tm_year) + str(t.tm_mon) + str(t.tm_mday) + str(t.tm_hour) + str(t.tm_min) + str(t.tm_sec)

link = 'http://ift.tt/19wWrtU' +datetime + '/test'

When I try to acess the link, in aws console it appears like this: http://ift.tt/1xT03C5

And it works, I can acess the above link.

But if I try to acess the link in the way Im saving it, like this:

http://ift.tt/19wWrtW

Im getting a xml with an Error "<code>AcessDenied</code>"

Do you see why Im getting this error?