Zotero changed the date of items with no dates, to "1970-1-1"

mibigo

Hello,

I realised that some weeks ago, Zotero has arbitrarily changed the date of some 400 items that I had left with an empty date, on purpose; it changed all dates to "1970-1-1" autonomously.
Moreover, it does not let me change it back to empty, if I delete the date it fills it again with 1970-1-1.

I don't see the need to do that, but maybe you have an explanation. However, it's quite annoying, as I need these Items to be left with an empty date.

They refer mostly to websites sources that I need to keep on top of each folder, and that I cite very often. Bibliographically speaking is not very correct, but it serves my needs, and by the way I can always use a style with a "last accessed on xxx-xx-xx" if i want to let people know when I last checked that site/sources

Can anyone tel me if there is some setting I need to change and why Zotero all of a sudden decided that there cannot be empty dates items?

Best regards
Michele

adamsmith

That's certainly not intended behavior -- empty dates are very much possible and allowed. We've also not had any other reports of this, even though I'd assume most users have items with empty dates in their library.
Are you using any add-ons (other than the standard Zotero Word/LibreOffice add-on) or have performed any bulk actions in your library using API or Javascript (if that doesn't mean anything to you, you haven't)?

If the answer for both of these is "no", could we get a debug ID for trying to clear out the date that covers it changing back?
https://www.zotero.org/support/debug_output

mibigo

Thank you Adam, for your prompt reply. Now that you make me think I have indeed some add-ons that I wanted to test further to the usual word and libre-office plugins. They are the following:
Folder import to zotero
Zotero Abstract Cleaner
Zotero Preview
Zotero date from last modified
Judging from the name this latter looks like a likely culprit.. however, reading the github page (https://github.com/retorquere/zotero-date-from-last-modified) it seems inoffensive..,
this is the debug item D1331186420; I simply added a web page, and it set the date to 1970; so maybe if there is no date in the url it sets it to this default date.. however, at the worst, it could have done that only for new items I added since I installed it; how could it have changed all empty-date items I already had in my library and in one go?

I can remove these add-ons, but can I set back all these items to empty?

mibigo

An please see also this debug ouput (D1072966219), for when I try to clear out the date and Zotero (or the add-in) changing it

mibigo

It is clear that this add-on has to be the culprit. I removed it and I can now change back the date to empty.. However I still do not understand why and how it changed all previous 400 items date in bulk..

so is there a way to change all them back to empty date, in one go. ? I remember there was no possibility to do bulk editing actions, is it still the case ?

adamsmith

I can't explain the 1970 (which looks like some fallback date), but the add-on does exactly what it says it will in terms of populating the date field:

If the date field is not filled, and the URL field is, fill the date from URL last-modified automatically after an item changes.

It's possible to empty out the date field of all items with a certain value using javascript, basically as described here: https://www.zotero.org/support/dev/client_coding/javascript_api#exampleitem_field_changes
but make sure to turn off sync, back up your library, and you may have to experiment with the exact format the 'is' operator expects for dates.

fcheslack

For reference, the 1970 date would be from a value of 0 for a unix timestamp.

mibigo

Thank you both. Where do I find a list of Zotero fields names? in the page you mention there are some examples, but I have to know the exact name of the field to change ; I guess is "publicationDate", but I would like to look at a complete list of fields.

adamsmith

It's just date -- the field list is https://api.zotero.org/itemFields?pprint=1 (linked from that page, too)

mibigo

Thank you!