wget: Checking for file timestamp and overwriting.
How can I get `wget` to do this:

Download a file from a location say `x`, only if the local copy of the file has an older time stamp than that of the file's time stamp on `x`. That means, it should download a file from a given location, only if there is a newer version of the file.

In case there is a newer version of the file, `wget` should overwrite the file. 

Is it possible to do this?
wget: Checking for file timestamp and overwriting.
===

How can I get `wget` to do this:

Download a file from a location say `x`, only if the local copy of the file has an older time stamp than that of the file's time stamp on `x`. That means, it should download a file from a given location, only if there is a newer version of the file.

In case there is a newer version of the file, `wget` should overwrite the file. 

Is it possible to do this?