Bukkit

well it is realy easy
you got 5 commands:

/hacksafe log
you load everything in the log of yeasterday whit this.
/hacksafe date <day><month><year>
you can set the date whit this(it wil reset it self if you reload or stop the server!)
/hacksafe time <hour><min><sec>
you can set the time whit this(this wil also reset it self when you reload or stop the server)
/hacksafe set kick <true/false>
enables or disables non-recommended IP kick.
if this is enabled the server wil kick the user when he didn't login on the recommended IP of the player.
by default is this false.
/hacksafe ip <IP>
you set a recommended IP whit this

for the server admin:
it is important to set the time and date when you start up the server for the player logs!