Time handling in F-spot

[Paul Wellner Bou <paul purecodes org>]

Hi,

Once again, I want to bring up the time handling topic in f-spot, as we 
discussed this lately in irc. For me, it is just annoying that F-Spot is 
displaying the wrong dates and I have to look at the Exif (of the RAWs, 
where I can trust they are untouched) to look up the real date.

If I import a photo in F-Spot which is taken on 2009:06:17 08:59:55 
camera time (and in this case, local time, too), F-Spot modifies this 
time to 2009:06:17 06:59:55. This leads to 1) _a wrong time_ and 2) if I 
were in a timezone later than UTC, a digitized time (in exif) before 
original time, which does not make sense, and 3) On reimporting photos, 
F-Spot will shift the time by the same amount again!

The time changing in F-Spot does not fix any time zone switching in any 
way. If I travel to Thailand, set the camera to the Thailand local time, 
shoot some photos there, and import them in F-Spot, F-Spot still will 
shift the time by the same amount (in summer time CET two hours).

While sorting the photos by time (which, of course, should be correctly 
done by (real, not assumed) UTC time, if available) it does not make any 
difference if the original exif time is left or the original exif time 
of _all_ photos is shifted by the same time offset.

In my eyes there are only two ways of solving this time zone problem. If 
you disagree, please tell my -- and why.

1. Allowing the user to set the timezone of the camera time on importing 
the photos.
Summarizing the feedback on IRC: No option, as it would make the import 
more complicated.

2. Not touching the original exif date in any way on importing. 
Adjusting time and setting time zones could be done then in the adjust 
time dialog.
Feedback: a) No, this is the "worst option" to fix the time problem, b) 
This is the right way to do it.

I prefer option 2. I created a branch on gitorious which prevents time 
shifting in f-spot. Just the exif date will be taken. It works and I am 
using it, but it may be uncomplete and buggy.
http://gitorious.org/~paulwb/f-spot/paulwbs-clone/commits/ImportTimeHandling

Further, I think that F-Spot shouldn't change/save any time related data 
permanently without the time zone. So the original exif date should not 
be touched if not explicitely requested by the user (in the case the 
camera time was set wrong for example).

Are there more ways for time handling which solves the 
missing-time-zone-in-exif problem? How would you do it?

Regards
Paul.