> The top Stack Overflow answer on robots.txt has a discussion about Allow: / not being valid according to the spec. The only date for the comments is "Over a year ago" but given that the question is from 2010 the comments are probably from around that time.

Firstly, I detest that stupid "feature" of showing only relative dates. It makes screenshots impossible to date, and it's frankly useless for humans as proven by OP's article.

Secondly, you can hover over the relative date string to see the actual date. But don't let that stop you from hating it.