It depends whether you want to see age or point in time, a.k.a do you want to compare it to now or to some other specific time. I personally take longer to par

It depends whether you want to see age or point in time, a.k.a do you want to compare it to now or to some other specific time. I personally take longer to parse an ISO formatted timestamp when all I want to know is age (i.e. difference from now). An "x [unit] ago" is much faster for me. The absolute timestamp is probably more handy when I have other dates to compare it to, because I could line them up vertically and visually diff the digits. I think it boils down to the fact that I don't have enough working memory to precisely memorize all numbers in a complete timestamp.