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 #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

2022-09-03_logseq-date-format-handling.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?

[diegodlh]

What about having an option, when preferred date format is changed from the settings, to optionally change journal backlinks as well? For example, if current configuration is MMMM do, yyyy and user wants to change it to yyyy-MM-dd (actually my case right now), in addition to asking the user to re-index, we may ask the user whether they want logseq to find any MMMM do, yyyy-format backlinks and change them to yyyy-MM-dd format. What do you think?

Alternatively, just having an external tool that does this would be very helpful already. Does anyone know one that does this already?

Edit: I've managed to do this manually running the following lines:

sed -i -E "s/\[\[January ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-01-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[February ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-02-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[March ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-03-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[April ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-04-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[May ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-05-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[June ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-06-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[July ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-07-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[August ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-08-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[September ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-09-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[October ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-10-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[November ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-11-\1\]\]/g" pages/* journals/* 
sed -i -E "s/\[\[December ([0-9]{2}), ([0-9]{4})\]\]/\[\[\2-12-\1\]\]/g" pages/* journals/*