I don’t think you can use Ymd in the blueprint for the date picker, the default is YYYY/MM/DD, while Ymd is the default for the date format prepended to the folder name. Valid formats for the folder number date are php date formats as described here: http://php.net/manual/en/function.date.php.
@anon77445132: Format dd.mm.yy is perfectly valid as date format for the date picker field, while Ymd cannot be used there
The format as displayed in the panel is different from the date displayed in the text file, so if you put format: dd.mm.YYYY in the blueprint, it will still translate to 2015-10-16 in the text file, that is perfectly all right.
The format Ymd is default anyway, so you don’t need to specify this in the blueprint, you need to do this only if you want to use a different format.
Anyway, I’ve been testing so many things in the last few hours, it could be that I had yyyy-mm-dd before on my blueprint. Doesn’t really matter. The issue here is the content. It’s storing the right date in the content file but the wrong date on the folder filename. Why is that?
And you know what’s really funny? All the subfolders (the subpages) used to start by 20150324 yesterday and today they start by 20150325. I have like 20 entries (subpages) and I’m sure I did not edit 90% of them (I’m testing everything only with one entry). How’s that all folders got renamed to today’s date?
I briefly tested this and it seems that the date you enter in the text file via the date picker has no effect whatsoever on the folder date. Looks like it takes the day you set the folder to visible is taken as the date, i.e. if you set the article to invisible and then change back to visible, it prepends 20150325, i.e. today