[Lucases]

Download TimestampToDate include

Then just save the current timestamp when an admin types the command to ban him, and the second time stamp.
Like you know 1 hour is 60 seconds * 60 minutes

So 1 hour is 3600 seconds

Make a command with sscanf and let the admin type the number of hours

Then do
Secondtimestamp = gettime() + hours*3600;

And save it

When a player logs in, do this

if(secondtimestamp < gettime() )
Then their ban expired, if not kick them