Especially when sharing a ccache with other users in a large team environment, it can be difficult to know by whom or when the ccache stats were zeroed.  It would be nice for ccache to print this as part of the stats.  For instance:

$ccache -s
ccache stats since Wed Feb  3 18:28:42 EST 2016
cache directory                     /path/to/dir
primary config                      /path/to/dir/ccache.conf
secondary config      (readonly)    /usr/local/etc/ccache.conf
cache hit (direct)                   100
cache hit (preprocessed)             100
cache miss                            10
...