Date sorting glitch

[Capnm]

The tweak "Control how dates are displayed" is set to the default
("gui_timestamp_display_format = 'dd MMM yyyy'")

The tweak "Choose whether dates are sorted using visible fields" is set to true
("sort_dates_using_visible_fields = True")

Sorting on the Date (timestamp) column appears to sort on yyyyMMddam, instead of the expected yyyyMMdd. That is to say, within a given day all the am timestamps sort as equal, and all the pm timestamps sort as (a different) equal.

(Incidentally, the am/AM documentation did not make it into the tweak help box, nor did the last_modified default if not set)

(And I could swear you mentioned iso as a formatting option somewhere ... should that be documented?)

Thanks!
(0.8.26)

[Kovid Goyal (kovid)]

Changing the component for this bug.

 assignee cbhaley
 status triaged

[Charles Haley (cbhaley)]

Sorry, but I don't understand what the problem is.

Guessing at what it might be, as a test I set the titles and timestamps on 3 books to be
title 1, timestamp 2011-11-08T13:16:26,
title D, timestamp 2011-11-08T11:21:57, and
title T, timestamp 2011-11-08T13:16:27.

After setting the display to dd MMM yyyy, I sort by title ascending, and then by timestamp descending. The three books end up in ascending title order within the timestamp, which means that the time including am/pm is being ignored. If any part of the time was considered significant, the titles would not be in the correct order.

What is it that you are seeing? Can you give examples?

[Capnm (mgbrown)]

???!

That's pretty much what I have --
Several books @ each of
2011-11-07T03:xx:xx
2011-11-07T09:xx:xx
2011-11-07T21:xx:xx

As you, I set the display to dd MMM yyyy, I sort by title ascending, and then by timestamp descending.

The T21: books are first, in title order, followed by the T03: and the T09: as one group together in title order.

Sorting by timestamp ascending again gives two groups, the T03/T09 group followed by the T21 group.

I don't know if it is significant, but I haven't touched these timestamps -- they were created under 0.8.23.

am/pm seemed the obvious explanation ?puzzled?

When I have a chance I'll copy some books to a clean library, and if the problem persists, upload the metadata.db if that would help.

[Capnm (mgbrown)]

Almost forgot ---

I tried setting the display tweak to "dd MMM yyyy-hh"

And it sorted in three groups, each sorted by title, as expected.

[Charles Haley (cbhaley)]

Found it. The problem has to do with timezone correction. I changed the date/times to UTC, which in some cases can cause the date to move forward or back a day. For example, if you live in US Eastern time (UTC+5h), then times after 19:00 will move forward a day.

My fix is to use localtime instead of UTC. Although the time will still be corrected, it should work because localtime is what is being displayed on the GUI. You will be sorting on the values corrected in the same way as what you are seeing. At least I hope so.

[Kovid Goyal (kovid)]

Fixed in branch lp:calibre. The fix will be in the next release. calibre is usually released every Friday.

 status fixreleased