I was very confused when I saw in a grep.. /var/log/yum.log:Jan 25 12:48:39 Installed: krb5-libs.i386 1.3.6-2 as it's only 11:54 right now, and the clock is correcyt. Turns out, this is from Jan 25th 2005.
The yum log matches the format used for syslog.
the difference being syslog are logrotate'd so you can be fairly sure the dates in the current logfile are 'now'.
*** This bug has been marked as a duplicate of 174969 ***