[JimmXinu]

This is mostly good, but there are some additional nuances.

How timestamp, pubdate and last_modified appear can be customized in Calibre Preferences > Tweaks > "Control how dates are displayed". I suspect that the default appearances are based on locale, but I could be wrong.

All three are internally stored with time as well as date. So tweaking the appearance may reveal previous stored, but hidden timestamp precision.

Originally Posted by dailyalice

The column with the column header of "Date" and the lookup name of "timestamp" is literally for when you added a work to your calibre library. I find this handy if I want to sort my library based on the items I've added to it most recently. It appears to use the default format of dd MMM yyyy (which would give you dates like 28 Sep 2022).

That is how Calibre treats timestamp. FFF by default updates timestamp when ever a downloaded book is updated. This can be changed by checking FFF's Config > Standard Columns > Date New Only.

Originally Posted by dailyalice

The column with the column header of "Published" and lookup name of "pubdate" is used for the date a work was published; it appears to only include the month and the year (MMM yyyy); if you want something more specific than that which includes the day of the month, you'll want to create a column for FanFicFare to use. These dates look like "Sep 2022" in calibre.

pubdate can be tweaked to show more precision, no added custom column needed. The column does record time as well as date. Not all FFF supported sites have pubdate with time, but for those that do, it is set in pubdate.

Originally Posted by dailyalice

The column with the column header of "Modified" and "Lookup name" of "last_modified" tells you when you last edited a work or made any changes to it. It also uses the default format of dd MMM yyyy. I just tested this by editing the metadata of a work to remove a single tag; now the "Modified" date is for today's date.

I would note that last_modified can change unexpectedly sometimes.

For example, if you have FFF downloaded books with the same author name but from different sites, downloading one may change the author URL for that author name. When that happens, all books with the same author name (even from different sites), will get the new author URL and last_modified reset. Or if a tag is changed in the tag browser, all books with that tag will have last_modified reset.

This is something that surprises Calibre users in general fairly regularly.

Originally Posted by dailyalice

What about FanFicFare? The items which can be put into custom columns with a date column type are: Published, Updated, & Created. If you create custom columns to use with this data, you can format the dates however you like.

I would emphasize the difference between standard and custom columns more, including the fact custom lookup names all start with # and that the user must create them.

Originally Posted by dailyalice

"Published" is the publication date, which actually does include the month, day, & year info (as opposed to calibre's Published column which just has month & year).

Again, tweaks for Calibre pubdate. And some sites have time, too.

Originally Posted by dailyalice

"Updated" is when a work was last updated (by the author on the archive from which you downloaded it) and it also includes day, month, year.

"Created" is usually labeled "Packaged" by FanFicFare (this is defined in personal.ini & can be changed) and is the date (& time) when you downloaded a work (using FanFicFare).

Updated in FFF also has time on some sites. Easiest way to know which sites is to search in defaults.ini for _format. Created/Packaged always has time.

Originally Posted by dailyalice

And there's also the special column "FFF Updated" which covers "the last time FanFicFare updated or checked for updates" which is different from when you last edited anything having to do with a work or when a work was updated.

I wouldn't describe this has a 'special column', but as a FFF custom column setting. And it's labeled 'Last Checked Column' under FFF Config > Custom Columns. I assume 'FFF Updated' is your name for the column.