When changing between date formats backlinks to journal pages aren't valid anymore and pages with dates are created

[defaulvlan]

What happened?

(Info: this issue might relate to https://github.com/logseq/logseq/issues/6377 )

When you have the date format EEEE, yyyy/MM/dd pages like Friday, 2022 or Saturday, 2022/09 are generated when you create a journal page. (weird, but journal pages still working at this point)

When you change the date format to something else like yyyy-MM-dd all backlinks to journals aren't valid anymore.

(additional info: In my personal graph with EEEE, yyyy/MM/dd I currently can't re-import the graph if I delete \AppData\Roaming\Logseq - not all, but some journal pages missing, although the markdown data is in journals folder.)

Reproduce the Bug

1. Create a new graph
2. Set date format to EEEE, yyyy/MM/dd
3. Re-Index
4. Create a page and link to one or more date with native logseq functions like /today or /date
5. Visit links with date
6. look at All pages there are journal structured pages there (not intended, right?)
7. Change date format to yyyy-MM-dd
8. Re-Index
9. Previously created "date links" to journal go to "normal" pages and aren't linked to the journal anymore

Expected Behavior

• No auto generated pages like this: if you interact with them they get written to the pages folder

• Links to journals should work, although you change date format

• I'd expect logseq would recognize every format it offers in Editor -> Preferred file format

Screenshots

https://user-images.githubusercontent.com/106736889/188286493-b0d16195-0a61-49f2-9ebe-e4f28aa1c40b.mp4

Desktop Platform Information

Windows 11 any build Logseq 0.8.4

Mobile Platform Information

not tested

Additional Context

No response

[defaulvlan]

I don't know if it aligns with your design principles for logseq, but maybe it's an option to save the date in a standardized format like ISO 8601 to disk and render it differently in the frontend based on user selection.

[cnrpman]

@defaulvlan Yes, the original dates will be invalid for now. It's not related to #6377

Using unified format to store sounds good to me. I'm happy to review any PR on this.

[itsamemarkus]

Thanks for the info. I just wanted to add that for me this is also a data stability issue.

Because for my one graph where I changed the date format to EEEE, yyyy/MM/dd a few month ago I cannot successfully reindex without losing journal entries. (with losing I mean the markdown files are there, but data is not visible in Logseq)

Only the data in \AppData\Roaming\Logseq keeps it working currently. If I transfer my logseq data directory (markdown, settings etc.) to a fresh Windows install I cannot get the current state back.

[cnrpman]

@itsamemarkus Is this happening on the latest version?