Imprecise Dates

[BetterRed]

Does anyone have a solution for dealing with dates that are sometimes imprecise, in that sometimes you have a year, at others a year and a month and at others a year, month and a day..

I don't like having pretend dates as in 1985-01-01, I would rather have something like 1985-??-?? or 2014-05-??

BR

[capink]

You could use a composite column with conditional formatting. Problem is how would you tell whether a date like 1985-01-01 is an actual date or a pretend date?

If you will presume that every date that starts with 01-01 is a pretend date, a template like this should work:

program:
	m = format_date(field('timestamp'), 'M');
	d = format_date(field('timestamp'), 'd');
	if m == 1 then
		if d == 1 then
			format_date(field('timestamp'), 'yyyy')
		else
			format_date(field('timestamp'), 'dd-MM-yyyy')
		fi
	else
		format_date(field('timestamp'), 'dd-MM-yyyy')
	fi

[BetterRed]

IIRC composite columns are display only. I want to enter yyyy, or yyyy-MM, or yyyy-MM-dd into a custom column - and do it in the Book list. Maybe I could enter it as three parts (ints), and build a composite column from the parts for display purposes - but I'd need to validate the parts…

BR

[chaley]

I would consider adding 2 columns: one text column to enter the date and a composite column to display it.

You would enter the date using some version of a string that supplies the numbers and the desired format. Example:
Y,1984
YM,1984,12
YMD,1984,12,04
The template for the composite column would split the "list" into its component parts then reassemble them as desired. Something like:

program:
# date_string = field('#other_column')
	date_string = 'YMD,1984,12, 01';
	format = list_item(date_string, 0, ',');
	if format == 'YMD' then
		strcat(
			list_item(date_string, 1, ','), '-',
			list_item(date_string, 2, ','), '-',
			list_item(date_string, 3, ',')
		)
	elif format == 'YM'  then
		strcat(
			list_item(date_string, 1, ','), '-',
			list_item(date_string, 2, ',')
		)
	elif format == 'Y'  then
			list_item(date_string, 1, ',')
	else
			'Invalid Format'
	fi

[chaley]

Here is a more compact template that uses the list_split function that will be in the next calibre release (5.9).

program:
# date_string = field('#other_column')
	date_string = 'YMD,1984,12, 01';
	list_split(date_string, ',', 'li');
	if li_0 == 'YMD' then
		strcat(li_1, '-', li_2, '-', li_3)
	elif li_0 == 'YM'  then
		strcat(li_1, '-', li_2)
	elif li_0 == 'Y'  then
		li_1
	else
		'Invalid Format'
	fi

[BetterRed]

Thanks chaley, but in the middle of the night had an idea.

I made my #release/Release date column tag-like and hierarchical.

So, I can enter yyyy, or yyyy.mm or yyyy.mm.dd. Which suits me because I always write dates as four digit year, two digit month, and two digit day. Not sure if it would work for people write dates otherwise.

Aside: In the Tag browser:

If I click on 1986 I get books that that do not have a month specified, i.e. the search is always #mydate:(=1986), I expected it to be #mydate:(1986). Perhaps there needs to be a Tag Browser setting to specify if searches of hierarchical categories should create contains, starts with, or equals search terms.

If it exists, pray tell where 'tis - apart from advanced search.

BR

[chaley]

Originally Posted by BetterRed

Aside: In the Tag browser:

If I click on 1986 I get books that that do not have a month specified, i.e. the search is always #mydate:(=1986), I expected it to be #mydate:(1986). Perhaps there needs to be a Tag Browser setting to specify if searches of hierarchical categories should create contains, starts with, or equals search terms.

If it exists, pray tell where 'tis - apart from advanced search.

BR

For hierarchical categories the first click gives you an exact match, for example #text:"=2010". A second click gives you a hierarchical prefix match indicated by a 2-plus icon, for example #text:"=.2010", which selects all matching and child books. The dot is important, telling the search that you are looking for anything that matches X or anything that is a child of X. The same thing is true for "anything but" searches, but with a minus and 2-minus icons.

I don't know why you are seeing the parentheses when you click. I don't see them.

Why is it tag-like? Can you enter more than one date per book?

[BetterRed]

There is no option in the context menu Search flyout (which is where I started) to do a search that includes children, i.e. the equivalent of double click for keyboard addicts. So, when I found Single click was the same as Search->Search for 1986 I went looking for a setting.

The parentheses are in my mind, probably legacy of maintaining social distance between search terms, and I dunno why I made it tag like… seemed like a good idea at 4:20 in the morning

BR

[chaley]

Originally Posted by BetterRed

There is no option in the context menu Search flyout (which is where I started) to do a search that includes children, i.e. the equivalent of double click for keyboard addicts.

I will add context menu options to search for [not] X and children of X.

[chaley]

Originally Posted by BetterRed

seemed like a good idea at 4:20 in the morning

Perhaps you were worried about the covid variant and decided to inject bleach. That would certainly affect mental processes.