Validation error
 

Using epubcheck 1.0.5 as provided at:

http://www.threepress.org/document/epub-validate/

I get the following error for all FileName.epub:

# ERROR: FileName.epub/titlepage.xhtml(13): bad value for attribute "preserveAspectRatio"

If I edit the line in titlepage.xhtml file which reads:

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="100%" height="100%" viewBox="0 0 323 500" preserveAspectRatio="none">

and remove the part that reads: viewBox="0 0 323 500" preserveAspectRatio="none" or just remove the: preserveAspectRatio="none" I am able to eliminate the error. Can anyone tell me what the effect of this is edit is?

Is there a way to stop Calibre from writing the preserveAspectRatio="none"?

this is a bug in epubcheck. If you want to work around it, turn on the preserve aspect ration setting in the epub output conversion settings.

Thanks Kovid, you've done a great job with Calibre.

Is there any way to get Calibre to just output YYYY-MM-DD without the timestamp to avoid the erroneous error epubcheck reports:

ERROR ... .epub/content.opf(12): date value '2010-06-09 00:00:00-04:00' is not valid, YYYY[-MM[-DD]] expected

use the epub-fix command that comes with calibre

epub-fix
 

How do I use it?

Epub fix is a command line tool, read up on it here.

Is there any possibility to use/run epub fix in the GUI and not from the command line? Which gets quite tedious if you've got to fix dozens of files ...

You can write a shell script or a batch file, depending on your OS, to automate that. Look for documentation on using the for- loop in your OS' CLI.

Sorry, usually I write novels, but not batch files. ;)

Are you running windows?

I'll post this regardless of your answer for future reference:
On windows, paste this into a new text file:
and replace <command> with whatever command you want to run. Save with extension .bat in directory containing epubs, run from command line.
This will recurse through all subdirectories and run the command on all epubs it finds. If you only want to check/fix the ones in the current directory, use this instead: