iPhoto has a glitch: It populates old photos as the most recent with the year date in the future! 2106

Note that your date format only shows 06, not the 21, so there is probably not a difference here.

What happens if you select these photos, and from the image menu Image>adjust date and time?

Can you change the year there from 2106 to something more sensible? Or just change it to something, if it is missing? You need to type the 4 digit year quickly to stop it taking the first two digits as a two digit year.

Note with this method, you can select all the photos with the wrong year, and change them all in one step.

The second image gives a date of "06", which as already pointed out could be either 2006 or 2106. If you click on the image then press Cmd-I you'll get the Info panel which will display the full date.

In Library view, if you select all the images that have a date of 2106, and as already suggested click the Image menu and select Adjust Date and Time... you'll get a dialog like this:

Select the year, quickly type in 2006, then click Adjust. This will change the year to 2006:

Maybe it is time to move on from iPhoto? If it is a bug in the program, you cannot expect a fix.

Did you already “adjust date and time” on the photos? Perhaps you misunderstood what the command is doing. When you select several photos at once, the command will not set all selected photos to the adjusted date, but shift the date of the selected photos by the same offset. If some of the selected photos are having very different recent dates, their dates may be shifted to a date in the far future.