I found this, hope it helps.
How to change the number of days on my counter?
You can easily set your counter to any number of days. To do that, first sign in to your Counter Control Panel. You can do this by clicking your counter and following the instructions.
Once your Control Panel has loaded, you should see a reset button near the top of the page. Look for a button under the text, "Need to reset your counter?"
Click this button whenever you need to reset your counter or set your counter to a certain number of days.
Although the button will reset your counter to zero, a text box will also appear. Using this box you can set the counter to whatever number of days you want. You can use decimal numbers, so for 2 days and 12 hours, you would enter "2.5" in the box.
Don't forget to press return or click "Save"! After you are done, you should see the change both in the counter at the top of your page, and also in the forum. Your counter will continue to count up automatically, just like always.