strange log

[d_rob]

Hi
I found this in log, what it is
Dec 30 06:50:55 debian syslogd 1.3-3#33.1: restart.
Dec 30 07:13:36 debian -- MARK --
Dec 30 07:33:36 debian -- MARK --
Dec 30 07:53:36 debian -- MARK --
Dec 30 08:13:36 debian -- MARK --
Dec 30 08:33:36 debian -- MARK --