How to find out when was a photo taken?

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