Setting EXIF data from old images

[David Stahl <othernerd gmail com>]

All,

I am trying to put ALL of my digital photos into F-Spot and I've hit the
problem of 'What do I do with all of my old scanned images?'

I have probably close to 1,000 images that were taken with film cameras
and scanned in when I had them developed.

All I really care about is them showing up in approximately the correct
date-based order. Also, when the photolab scanned the images, they
usually did it in the order that they came off of the roll, so:

scan_image_roll01_001.jpg
scan_image_roll01_002.jpg
...
scan_image_roll02_001.jpg

are in the order that the images were taken.

Is there an easy way to set the EXIF date for these? I've fooled around
with 'exiv2', but I'm not sure which tag to set for the date that F-Spot
uses. DateTime? DateTimeOriginal? Are those even real tags? :) 

I'd be happy to be able to take a bunch of images, sort them based on
the filename, and then specify a starting date/time and then increment
the time by a minute for each one so that they get sorted correctly by
F-Spot.

So I've got two main questions:

1) What tags need to be set so F-Spot works correctly?
2) Has anyone already done this?

I've written some Ruby scripts to read EXIF tags and sort images into
folders based on some values in there, so I'll probably tweak one of
those to do what I need here.

-D