how do I change the date on multiple pictures

How can I change the dates on multiple pictures?

In Photos you can change the date and time using the "Adjust Date&Time" command. If you select multiple photos, the dates will be shifted for all selected photo by the same offset. The command is meant to be used for photos taken with a camera, if you forgot to set the clock in the camera correctly, and need to shift the date and time by the same amount.

This command is not very practical for scanned images, however, if you want to set multiple selected photos to the same date and time. You would have to adjust the date and time for each photo individually.

You could try an AppleScript I posted. It will change the time of several selected photo at once to the same date as the first selected photo has, and add a short increment of time between successive photos, so you can sort them by the time.

See: Script: Batch Change the Date and Time to a Fixed Date

To use this script, adjust the date and time of the first photo, then select all other photos to and run the script.

With Photos 2.0 if you select multiple photos and use the adjust time/date command the times and dates of all the photos will be adjusted by the same amount

As Léonie says this may not be what want for scans - probably the script she links to is what you want

LN

Depends on undisclosed details - you posted in the Photos for Mac forum and state that you have iPhoto '11 - what version of the OS and of iPhoto or Photos do you actually have?

Basically you select the photos and use the change date/time command but without knowing what software you have we can not give specific instructions

LN