Entering a partial date?

[Kythe42]

Hi, I'm new to this forum.

I've been using Calibre to manage my ebook collection for quite awhile and I didn't really care too much about having lots of metadata.

Now I've decided to make a separate library for the purpose of tracking my reading in case sites like Shelfari, GoodReads, and LibraryThing disappear. As such I've been making a whole bunch of custom columns. One of the many things I'm tracking is the dates that I've read books. The problem is that for a bunch of my books I really don't know the exact date I read the book. Sometimes all I know is the year.

It seems that Calibre doesn't want to let me set a partial date, either with just the month and year, or year alone. I'm pretty sure I was able to do this when I was experimenting around with this in previous versions of Calibre. If I remember correctly there used to just be three different drop-down menus for day, month, and year and it was possible for me to leave some of them blank. Now in the current version it pulls up a little calendar and makes me do a complete date.

I've tried doing the dates as text fields, but unfortunately they won't sort properly with partial dates unless I either do the dates in reverse order(2012/08/22) or put in zeros for the day and/or month for the partial dates(00/00/2012). Neither of those options looks that great in my opinion and preferably I'd like the month spelled out.

Does anyone know if there's a way for me to set partial dates using the custom date fields?

Thanks in advance for any help you can give me.

[Adoby]

One way could be to move to Sweden.

Here we write dates in the sensible way as 2013-08-12. Also known as ISO date format.

Other than that I would recommend that you use the date fields already present in calibre, but change them to only show what you want them to show.

More about different ways to change date handling in calibre can be found in this recent thread.

https://www.mobileread.com/forums/sho...d.php?t=219838

[Kythe42]

Thanks for your response. While I agree that 2013-08-12 would be a more sensible format, it's not what I'm used to.

As for your suggestion to change the date fields to show only what I want them to show, are you suggesting that I make 3 separate date fields for day, month, and year and then compile them into a composite column? This does seem to work(at least based on brief testing), but it's rather cumbersome, especially if I want to input multiple dates(dates started and finished reading for example).

Obviously if I go with that option I'm not going to have all the individual date fields showing in spreadsheet view and I'd want to enter that data by going to the individual book pages. The problem with this is that the fields in the custom metadata tab insist on being displayed in alphabetical order regardless of what order I stick them in for spreadsheet view. This is already annoying enough for me having to jump around all over the place to edit metadata, but will be a lot worse with all the individual date fields and I want at least two sets of dates. I don't suppose there's a way to change the order of these fields that I'm not currently aware of?

[Adoby]

I don't think there is a good solution for you. Except ISO format dates in plain text fields, but I understand the cultural problems you have with that obvious solution...

One other thing that you might want to examine is the possibility to enter complete dates. dd mm yyyy, but only display years.

There is a calibre template function that allows you to reformat dates, format_date. Perhaps that could be used somehow?

http://manual.calibre-ebook.com/template_lang.html

[Kythe42]

Thanks for the link. Funny enough I was actually reading that page earlier today to figure out how to format the composite column, but I didn't see the section on format_date. I'm not really sure how to use it though to reformat a text field in which I'd use the ISO format in order to make the date appear in a more familiar format. I suppose this is beyond my current skill level.

It's just so frustrating that I should have to go to such great lengths in order make sortable partial dates(in the format of my choosing), which is something that I'm pretty sure Calibre used to be able to handle without any problem.

Perhaps if I go with the separate date fields with the composite column option, I can better organize how they show up in the custom metadata tab by the way I name them. They would all be together if I named them "Date Finished Reading Year", "Date Finished Reading Month", and "Date Finished Reading Day" rather than "Year", "Month", and "Day".

Thanks again for the suggestions. If you have any further thoughts, please feel free to share them.

[chaley]

Originally Posted by Kythe42

It's just so frustrating that I should have to go to such great lengths in order make sortable partial dates(in the format of my choosing), which is something that I'm pretty sure Calibre used to be able to handle without any problem.

Custom date columns do have formats of your choosing. Once you set a format you enter dates in that format. If parts of the date aren't included in the format then they aren't required to be entered.

For example, see the attached screen capture of a date custom column. It asks for year and month in yyyy/mm format. When I click on a cell, I enter exactly that.

However, there is no way to have a fully-populated date field where you can pick and choose what you enter on a case-by-case basis.

[Kythe42]

Originally Posted by chaley

However, there is no way to have a fully-populated date field where you can pick and choose what you enter on a case-by-case basis.

Well this is exactly what I want, so therefore I'm not able to do it in a format of my choosing. I honestly don't understand why this isn't possible. Didn't Calibre used to be able to do this, or am I crazy?

I just think that it's insane to need 4 fields(3 for the date and 1 composite column) in order to do full dates when I know them, but let me do partial dates when I only know partial dates, especially when I want to use multiple date fields(at least two and possibly as many as four).

This could apply to more things than tracking my reading. For instance, if I cared about when my books were published, I'd want to be able to enter a full date when I knew it, but still have the option of entering a partial date if I only knew the year, or the month/year.

Perhaps I should make a suggestion to the developers about this since I consider the ability to enter a partial date when needed to be an important function.

Thanks anyway for your response.

[theducks]

I don't ever remember being able to enter a non-fully valid date in a 'Date' type field... That would be an Database error if it got that far.
True Date types allow 'Date' mathematics to be performed in searches.

You can configure to show partial dates (or timestamps) in Tweaks

[Kythe42]

Well I think it was back in June that I was experimenting with custom fields and I don't remember having any problem entering a partial date. Back then instead of having a mini calendar pop up, there were just 3 mini drop down menus for the day, month, and year. I don't remember it forcing me to select values for day and month if I only put in the year.

Anyway I know about configuring a partial date in tweaks, but as far as I know I can't configure it to let me chose a full date, but leave the day or month blank if I don't know that info, which is what I'm to do.

[theducks]

If the just day is unknown, I use: 1

If I only know the year: 12/31 (a good flag..How many things are completed/released on the last day of the year? )

Date columns seem to have a variety of data entry modes, some restrictions are not totally obvious. You can Select the entire field, but not work with that. You must work only on 1 date section at a time MM/DD/YYYY

[chaley]

Originally Posted by Kythe42

I don't suppose there's a way to change the order of these fields that I'm not currently aware of?

Yes. See the tweak "Order of custom column(s) in edit metadata (ID: metadata_edit_custom_column_order)"

Originally Posted by Kythe42

Well this is exactly what I want, so therefore I'm not able to do it in a format of my choosing. I honestly don't understand why this isn't possible. Didn't Calibre used to be able to do this, or am I crazy?

I am the developer that did custom date columns, and IIRC for the 3 years I have worked on calibre there never was a way to enter dates using pull downs. Basically it can't work because in calibre a date must be a valid date, with all components having valid values. We can hide some of them and make up valid values for the ones that are hidden, but we cannot allow empty values for any date component.

Perhaps I should make a suggestion to the developers about this since I consider the ability to enter a partial date when needed to be an important function.

Won't happen for the reasons I noted above.

I just think that it's insane to need 4 fields(3 for the date and 1 composite column) in order to do full dates when I know them, but let me do partial dates when I only know partial dates, especially when I want to use multiple date fields(at least two and possibly as many as four).

You can do it in two fields, one text field with the date components in a known order and another composite column that "does the right thing" if components are missing. The following screen capture shows what I mean. "mytext" is the text column with dates entered yyyy/mm/dd. It is sortable because the components are in order of significance (y/m/d). "comp2" is the composite column that shows the partial date in whatever format you want.


The following shows the template for the composite column. It parses the values from the text field, then constructs dates using different date formats and values by checking if any of the fields are missing.

[Kythe42]

Thanks for your response Chaley. I apologize if I sounded a bit belligerent in previous posts. I don't know why I have such a strong memory of being able to do partial dates in Calibre, but if you're insisting as a developer that it was never possible, then perhaps my memory got jumbled up with other program demos that I briefly tested and ended up rejecting for one reason or another.

The two fields option while not ideal is certainly more manageable than four. Thank you for providing the screen shots as it really helps me to understand it in my head better as someone that has pretty much no python coding experience.

The one thing I'm missing though, and forgive me if it's something really obvious, but how do you get to the edit template screen you showed in the second screen shot? When I'm making a composite column it just shows a one line box to put in template code.

Also thanks for pointing out the custom column order tweak. I'll definitely play around with that later. It should as a whole make it much easier to navigate inputting my custom data

[chaley]

Originally Posted by Kythe42

Thanks for your response Chaley. I apologize if I sounded a bit belligerent in previous posts. I don't know why I have such a strong memory of being able to do partial dates in Calibre, but if you're insisting as a developer that it was never possible, then perhaps my memory got jumbled up with other program demos that I briefly tested and ended up rejecting for one reason or another.

Not a problem. I have been there.

The one thing I'm missing though, and forgive me if it's something really obvious, but how do you get to the edit template screen you showed in the second screen shot? When I'm making a composite column it just shows a one line box to put in template code.

I almost always edit the templates after I create the column. To do this, create the column with any template, click on any cell in the column, then press F2. The template editor will open.

[Kythe42]

OK, thanks. I was able to get to the template editor and put in the code you gave me, with one or two tweaks to get the date format exactly how I want it. So far it seems to work, but what really surprised me was that it correctly formatted all the cells I had already entered in the text date field in the format of 06/02/2013 as June 02, 2013. So I guess it's not actually necessary for me to enter the text dates in ISO format(2013/06/02) if both ways work. I also tested it in the UK date format which would be 02/06/2013 if I remember correctly. That way did not work and it interpreted the date as February 6th. If the code working for both formats(2013/12/31 and 12/31/2013) is a bug and you intend to fix it in future updates, please let me know so I can change all my dates to ISO format ahead of time.

There are one or two other things. If an entry has nothing in the text field, then the composite column just shows the current year, 2013. Is there any way to get the composite column to show up as blank until a date is actually entered in the text field? It's not a huge deal I guess, it's just that in order to make adding my entries a bit less tedious I added 100 empty books when I started this library, so I've got lots of blank entries that show 2013 as a date.

I'm also wondering if there is a way to change the way that partial and full dates are sorted together? If I'm sorting them ascending then it will show the full dates first, then the dates where there's just the month and year, and the the dates where there's just the year last. So for example:

April 08, 2012
April 2012
2012

Preferably I'd want to see them in the reverse order from least complete dates to most complete dates. This doesn't actually apply to my needs because I only have full dates for books I've read starting in 2013 and all books read before 2013 I only have the year, but I'm just wondering if it can be done for curiosity's sake.


Edit: As an afterthought I tried testing a partial date with the month and year in the US format 11/2012 and that didn't work with the code even though the full dates(and obviously just the year) were fine.

I also did more testing on the sorting issue and I'm really bewildered now. Entries marked with just the year actually seem to be sorted in between July and August dates. As in:

March 2012
April 2012
May 2012
June 2012
July 2012
2012
August 2012
September 2012
October 2012

Again, this isn't actually an issue for me with my specific sorting needs, but it really doesn't look right at all sorted like that and I can see how it might be annoying for some people.

[chaley]

Originally Posted by Kythe42

OK, thanks. I was able to get to the template editor and put in the code you gave me, with one or two tweaks to get the date format exactly how I want it. So far it seems to work, but what really surprised me was that it correctly formatted all the cells I had already entered in the text date field in the format of 06/02/2013 as June 02, 2013. So I guess it's not actually necessary for me to enter the text dates in ISO format(2013/06/02) if both ways work.

The date parser tries hard to understand the value passed to it.

That said, the only way the text column will sort correctly is if you use yyyy/mm/dd values.

I also tested it in the UK date format which would be 02/06/2013 if I remember correctly. That way did not work and it interpreted the date as February 6th. If the code working for both formats(2013/12/31 and 12/31/2013) is a bug and you intend to fix it in future updates, please let me know so I can change all my dates to ISO format ahead of time.

This is not a bug unless you are in the UK and using UK locale settings. When a date is ambiguous, the date parser checks the locale and chooses the month and day from that.

There are one or two other things. If an entry has nothing in the text field, then the composite column just shows the current year, 2013. Is there any way to get the composite column to show up as blank until a date is actually entered in the text field? It's not a huge deal I guess, it's just that in order to make adding my entries a bit less tedious I added 100 empty books when I started this library, so I've got lots of blank entries that show 2013 as a date.

Change the template to check for an empty field. You would check it first using something like test(y, stuff that is already in the template, '');

I'm also wondering if there is a way to change the way that partial and full dates are sorted together? If I'm sorting them ascending then it will show the full dates first, then the dates where there's just the month and year, and the the dates where there's just the year last. So for example:

April 08, 2012
April 2012
2012

Preferably I'd want to see them in the reverse order from least complete dates to most complete dates. This doesn't actually apply to my needs because I only have full dates for books I've read starting in 2013 and all books read before 2013 I only have the year, but I'm just wondering if it can be done for curiosity's sake.

I think that if you use yyyy/mm/dd format in the text field then it will sort the way you want.

You might get away with sorting the composite column if you set the sort/search type to date, but I suspect that the partial dates will cause problems.

Edit: As an afterthought I tried testing a partial date with the month and year in the US format 11/2012 and that didn't work with the code even though the full dates(and obviously just the year) were fine.

You must be consistent, and you must change the template so it gets the values from the right place. It will be much harder to code the template if you don't use yyyy/mm/dd

I also did more testing on the sorting issue and I'm really bewildered now. Entries marked with just the year actually seem to be sorted in between July and August dates. As in:

March 2012
April 2012
May 2012
June 2012
July 2012
2012
August 2012
September 2012
October 2012

Again, this isn't actually an issue for me with my specific sorting needs, but it really doesn't look right at all sorted like that and I can see how it might be annoying for some people.

If you are sorting on the text column then you will get all sorts of bizarre results unless you are using yyyy/mm/dd format.