How to find out when was a photo taken?

I am trying to find out when some of the pictures I own have been taken. In Mac OS X, in Finder, I am looking at the photo. There is date created, but it is not correct. I assume it is the date when I copied the photo to Mac. The picture is taken in 2008, and the date is in 2009. I thought digital cameras store date when the picture is taken. There is all kind of metadata for the picture, but not date taken. I have checked for pictures taken by different cameras.

According to Exchangeable image file format article on Wikipedia, right click the image > Get Info > More Info should do it, but it does not. I can not believe that none of the cameras saved date taken.

Am I doing something wrong? How to see when the picture was taken?

I have access to Mac, Windows and Linux machines, if it is easier to see in any of them.

Found it in Preview.

Tools > Inspector > More Info tab (in the middle) and then Exif of TIFF tab.

I am still not convinced the actual time when the image was taken is recorded there, it looks to me that in some cases the time when the image was moved to a computer is there, but that could be camera specific. Good enough for now.

I googled to find this link. It is a program called 'exifme' which retrieves the date and time info.

http://otvox.com/exifme.htm