If you are not already, I would recommend reimaging the Macs during summer and winter breaks. Either way, you can do this with a script which Jamf can deploy. You can make the script as fancy as you want. Keep in mind, automating data deletion can be very risky.
An example I tossed together; I have not tested this at all and likely wont run as is. Just an idea for a workflow.
#!/bin/bash
# Get the current date in seconds since epoch
current_date=$(date +%s)
# Iterate over all user accounts
while IFS=: read -r username _ _ _ _ home_dir _; do
# Skip the "Admin" account
if [ "$username" == "Admin" ]; then
continue
fi
# Skip system accounts and non-existent home directories
if [[ "$home_dir" == "/var" || ! -d "$home_dir" ]]; then
continue
fi
# Get the last login date for the user in seconds since epoch
last_login_date=$(dscl . -read "/Users/$username" | grep -A 1 "LastLogin" | tail -n 1 | awk '{print $2}')
# Check if the user has not logged in within the last 30 days
if [[ -n "$last_login_date" && $((current_date - last_login_date)) -gt $((30 * 24 * 3600)) ]]; then
echo "Deleting user: $username"
# Delete the user account
sudo dscl . -delete "/Users/$username"
# Delete the user's home directory
sudo rm -rf "$home_dir"
fi
done < <(dscl . -list /Users UniqueID | awk '$2 >= 501 { print $1 }')
echo "User cleanup complete."
