With squid 3.4.5 my logs are broken now 10.x.x.x - fred [0%edR] "GET http://www.squid-cache.org/Versions/v3/3.4/changesets/ HTTP/1.0" 200 7799 TCP_MEM_HIT:HIER_NONE "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:29.0) Gecko/20100101 Firefox/29.0" logformat test %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh "%{User-Agent}>h" As you can see the date output is not correct, no problem on same machine with squid 3.4.4 Maybe this bug is already reported, sorry in this case, but I can't access bugs.squid-cache.org today Fred