Miana is a utility app for setting the creation and/or modification date and time of a folder and all of its contents to a specified date and time, and more.
Simply drag one or more files or folders on top of the Miana application icon in the Finder, or its status window. Use the Preferences window to set the date, time and various other options.
Miana is a member of the Limit Point Software Utilities Bundle : http://www.limit-point.com/Utilities.html. Purchase a Utilities password to activate all the utilities, including Miana. Upgrades are free, new utilities are always included.