BatchTouch

is a utility to batch-change the creation and/or modification date of files and folders. BatchTouch provides an easy-to-use way to change the creation and/or modification date of multiple files and folders all at once. It offers enough flexibility to the user to choose which type of items to change, whether or not to process the contents of folders, and whether to change the creation date, the modification date, or both. Furthermore, it is possible to change just the time, just the date, or both. It is possible to apply both absolute values as well as offsets to both date and time. I.e. it is possible to add/subtract a specified number of days, hours, minutes or seconds to/from the creation and modification date of any item.

Note: While the software is classified as free, it is actually donationware. Please consider making a donation to help support development.