How often is a new log file created when examining the log files from a Windows IIS Web Server?

A new log file is created everyday

We cannot tell if the question is referring to the httperr.log file (IIS 6.0) or is it referring to the logfiles for the website. If IIS is the case, a new log file is created every day should be the correct answer. Microsoft creates the log files in the following format: exYYMMdd.log format and rotates them daily.