To find the specific installation date of a Raspbian system, run the command ls -lt /var/log/installer to check for the installer log, or use tune2fs -l /dev/mmcblk0p2 | grep 'Filesystem created' to find the creation date of the root filesystem.

Methods to Find Installation Date:

• Log File Check: Run ls -l /var/log/installer in the terminal to see if an initial_setup.log exists. The timestamp of this file often corresponds to the installation time.
• Filesystem Creation Time: Use sudo tune2fs -l /dev/mmcblk0p2 | grep 'Filesystem created' to check when the SD card partition was created, which usually aligns with when the image was flashed.
• hostnamectl: Using hostnamectl can provide system information, though not necessarily the installation date.