How to get book file date into a column in calibre

[whitespirit]

Hi - I use calibre to manage my comics cbz-files which are sometimes updated. Everytime however if I add a colum or add a tag I get a new modification date without the file itslef has changed. I'm looking now to have the file (creation) date (as shown in windows explorer) into calibre a user defined date type column, but it seems very hard to use chatgpt as a platform to write a usable plugin that does so. Is there anyone capable of telling me what to do to get this work ? thanks

[theducks]

Not quite what you asked for...
If you hover over the format in the MDE, it will balloon the date.

[whitespirit]

Originally Posted by theducks

Not quite what you asked for...
If you hover over the format in the MDE, it will balloon the date.

Yes that's the date I want to have in the database as column so I can use it my catalog. I do not have a clue how to get it in there eg in custom column #cdate

[chaley]

Create a custom column 'Built from other columns' (a 'composite' column). Use the following as the template:

program:
	select(formats_modtimes('iso'), 'CBZ')

It could be that using a composite column will be too slow, given that it needs to read the disk for each book to get the modtime. You don't say how you use this data. If having it in book details is sufficient then hide the column in the book list, which will dramatically improve performace.

You can also use the Action Chains plugin to set the value of a date custom column to the result of the template on demand or when certain events occur. If you want to do this and need help then ask in the plugin's thread.

EDIT: you can also do it in bulk metadata search & replace using the above template as the source and the date custom column as the destination.

EDIT2: You can of course format the date using different format strings, for example

program:
	select(formats_modtimes('yyyy-MM-dd hh:mm:ss'), 'CBZ')

[theducks]

Originally Posted by whitespirit

Yes that's the date I want to have in the database as column so I can use it my catalog. I do not have a clue how to get it in there eg in custom column #cdate

Neither do I.
Be aware, that a few actions will change those files (date)
1)Embed metadata. 2) Polish 3) a same format conversion (commonly used to fix poorly coded files.

[whitespirit]

Originally Posted by chaley

Create a custom column 'Built from other columns' (a 'composite' column). Use the following as the template:

program:
	select(formats_modtimes('iso'), 'CBZ')

It could be that using a composite column will be too slow, given that it needs to read the disk for each book to get the modtime. You don't say how you use this data. If having it in book details is sufficient then hide the column in the book list, which will dramatically improve performace.

You can also use the Action Chains plugin to set the value of a date custom column to the result of the template on demand or when certain events occur. If you want to do this and need help then ask in the plugin's thread.

EDIT: you can also do it in bulk metadata search & replace using the above template as the source and the date custom column as the destination.

EDIT2: You can of course format the date using different format strings, for example

program:
	select(formats_modtimes('yyyy-MM-dd hh:mm:ss'), 'CBZ')

Thanks a lot - that's excatly what I needed in a very simple way !