friends list last online ?

Ok so I've been wondering why riot has not implemented this on to the client. Is it possible you could do this in an update i have reached my max and i would like to delete people that don't play that often i have close friends on league and i have people i add because they are good but then i don't see them for like months and then i go to add another and i don remember their name so i look through the 300+ friends in my friends list and i don't know who was on like 3 days 4 weeks 10 months etc. its a little frustrating it would be a lot of help if you could just look at your friends list and see hey this guy was on for like a year i don really know him either [zombie-nunu-tears] [zombie-nunu-tears] [zombie-nunu-tears] [zombie-nunu-tears]