Reply To: Can't get date to validate

You might have better luck if you don't replace the file when zipping it back up. Put the old epub somewhere else.

You could also try Oxygen Author, which lets you edit epubs without unzipping and without messing around with the file structure (as Sigil does). I show it in my InDesign CS5.5 to EPUB video at lynda.com. (just do a search for “oxygen” in my title there.)

AM