Each program contains two distinct timestamps; the “Created†timestamp and the “Last Modified†timestamp. The created timestamp is set when the project is created by the New Project option. The Created timestamp is not affected by any user edits or program compilation. The Last Modified timestamp is used to indicate when the user last modified the program. There are many conditions that cause the Last Modified timestamp to be set, it includes Edit of instructions or operands in the program, Adding, deleting, or modifying a Local or Global Symbol, Adding or deleting a POU, Compiling the program block and Downloading the program block .