[chaley]

Originally Posted by davidfor

Fiddling with the "DateLastRead" is not that useful as it changes as books are opened and hence the Recent sort changes. But, "___SyncTime" can be changed. My Kobo Utilities can update this to any date that is in the calibre library. I usually set it to the date column in calibre if I do a factory reset. That effectively maintains the date I originally added the book to the device. I have tried the published date, but, it isn't that meaningful to me for sorting.

This is done in the Update Metadata panel, changing Date Added? Setting it this way does work, but as you said it isn't useful for changing collection order because it is a per-book field.

For collections, there is a separate date added column for each book. At one time, the "Date added" sort in a collection used this. And the plugin has a function to set this so that book could be sorted by series or something else. That was before series sorting was added. But, from memory, the Date added sort in a collection now uses the ___SyncTime for its sorting. The function is still in the plugin. It simply set the timestamp and then incremented by a second for each book. I haven't tried it for a long time and haven't checked what happens when sorting the collections.

This is done using "Order Series" panel? This seems not to change how a collection is sorted by Date Added or Recent. Date Added uses the date I set using Update Metadata.

FWIW: I got this exception when changing Date Added in the Update Metadata panel to a date that is undefined for some books.

Spoiler:

calibre, version 5.42.0
ERROR: Unhandled exception: <b>TypeError</b>:'&lt;' not supported between instances of 'str' and 'int'

calibre 5.42* [64bit]  embedded-python: True is64bit: True
Windows-10-10.0.19041 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.19041')
Python 3.8.5
Windows: ('10', '10.0.19041', '', 'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: DeDRM (10, 0, 2) && Count Pages (1, 11, 2) && EpubSplit (3, 3, 0) && Fantastic Fiction (1, 5, 1) && Find Duplicates (1, 9, 5) && Kobo Utilities (2, 16, 0) && Modify ePub (1, 7, 3) && Open With (1, 7, 0) && Quality Check (1, 12, 0) && Reading List (1, 9, 0) && Save Composite Custom Columns (1, 1, 1) && Save Virtual Libraries To Column (2, 0, 1) && Save Virtual Libraries To Column GUI (2, 3, 0) && View Manager (1, 8, 0)
Traceback (most recent call last):
  File "calibre_plugins.koboutilities.action", line 958, in update_metadata
  File "calibre_plugins.koboutilities.action", line 4161, in _update_metadata
  File "C:\CBH_Data\calibre.git\calibre_dev\src\calibre\__init__.py", line 407, in strftime
TypeError: '<' not supported between instances of 'str' and 'int'