Linux is famous for its stability is a favorite among many system administrators and enthusiasts. One of the questions that often arises is how to find out the exact date and time the operating system was installed. This information can be effective for system maintenance, audits, as well as understanding the longevity of the system. Determining the exact installation date and time of a Linux OS can be challenging due to various factors like system updates, log rotations, and different distribution-specific methods. There are multiple ways to find out when a Linux OS was installed, each with its own use case and level of precision. Here, we explore all possible methods to retrieve this information, complete with explanations: