apt-config-auto-update software package provides Apt configuration for automatic cache updates, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install apt-config-auto-update
apt-config-auto-update is installed in your system.
Make ensure the apt-config-auto-update package were installed using the commands given below,
$ sudo dpkg-query -l | grep apt-config-auto-update *
You will get with apt-config-auto-update package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Utilities |
| Package | apt-config-auto-update |
| Version | 2.0.0-1 |
| Description | Apt configuration for automatic cache updates |
| Sub Section | Utils |