Is it possible to update timestamps on multiple photos using new Photos app? I'm using El Capitan 10.11.1 and Photos app 1.2

The new version of the the Photos app allows you to update the metadata for photos via the 'Get Info' menu option.  For a single photo, you can update the timestamp by opening the Info inspector, and double clicking the date/time.

The resulting Adjust date and time of selected photos dialog strongly implies that you should be able to do this for multiple photos at once.  It says:


  "The original date and time of your first photo is shown below.  Adjust it to the correct time, and all 1 photos will be time-shifted accordingly."


So... I have about 100 photos I need to do this to, but if I select them all (or any number greater than 1), the Info inspector changes subtly - the timestamp changes format from e.g. "11 November 2015 12:11" to simply "11 Nov 2015", and double clicking the date now does nothing except select the date in the Info inspector.

Is it possible to shift the date/time of my 100 photos within the Photos app?
Select the photos you want, then select the menu command "Image" -> "Adjust Date and Time..." which pops up the window that you are looking for. It seems as though it also gives control over the time zone for images with location data.

When adjusting the date/time of a group of photos, you adjust the date for one of the images, and all the other images time stamp is changed by the same amount, enabling you to correct for time zone shifts or improperly set camera date/time issues, rather than making the time/date of all the photos identical.