In help for ZIP
ZIP - Add, update, or delete files in a .ZIP archive
But a "ZIP /U /R" does also update files which are newer than files on disk.
ZIP - Add, update, or delete files in a .ZIP archive
| /U | Update files which either don't exist in the zip, or which are older than the files on disk. |
But a "ZIP /U /R" does also update files which are newer than files on disk.