Dropbox does not allow one to update the time/date for an uploaded picture via either the Web UI or the file tools; however, sometimes pics show up with either missing or incorrect dates in the Timeline.

This is particularly jarring when that information could be very easily inferred from a couple of obvious places: the file name (usually, of the form 2012-08-12 12.00.00-2.jpg) and/or the file’s modification timestamp (the latter, admittedly, wholly unreliable – but, still, better than nothing).

Dropbox’s timeline derives the time/date of the photo from the EXIF data, and in particular from the DateTimeOriginal attribute.

To correct this, it is a simple matter of using the exif tool and typing the following command in a shell:

$ sudo apt-get install -y libimage-exiftool-perl
$ cd ~/Dropbox/Camera\ Uploads
$ exiftool -DateTimeOriginal='2012-08-12 16:37:00' 2012-08-12\ 16.37.00.jpg

The original thread that explained this is available here; however, you don’t need to download/unpack and install exif tool – just use apt-get as shown above.

To find the name of the file from the photo’s thumbnail in the Timeline, simply right-click it and choose “Show in folder”.