I found one thing needs to be clarified in SQL 2005 server is when the time stamp of the MDF and LDF file being updated.
The reason why I am asking is that I noticed in a busy SQL environment, the time stamps of all the databases's MDF and LDF are many days behind, or even hardly updated since it is created over month ago. To my understand the LDF file should be updated once there is a log committed and the MDF file should be updated once the transactional log file backed up or the log truncated, therefore the MDF and LDF files' time stamps should be updated accordingly.
This include the system databases and user databases.
Can you explain why the time stamps of these files are far behind?