"time published in the consensus network status" seems to be wrong
I setup a watch dog script which informs me immediately about such log messages. I checked immediately the time. The time at my server was the same at my desktop and both seems to be accurate (set by ntpd).
That's why I do assume that this log
Jul 17 10:58:58.000 [warn] Our clock is 1 minutes, 2 seconds behind the time published in the consensus network status document (2015-07-17 09:00:00 UTC). Tor needs an accurate clock to work correctly. Please check your time and date settings!
points to an issue which has nothing to do with a wrong local clock of my server (F1BE15429B3CE696D6807F4D4A58B1BFEC45C822)