How to convert exported First/Last Seen times to a date format

Objective

After exporting a number of vulnerabilities to CSV format, you may notice that the "First Seen" and "Last Seen" columns are in epoch format:

"Unix time (also known as POSIX time or epoch time) is a system for describing a point in time, defined as the number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970, minus the number of leap seconds that have taken place since then." – Wikipedia

Converting these times to a more human-friendly date format is easy.

Process

Once you have opened the exported vulnerability report (in CSV format) into your spreadsheet editor (e.g. Excel)

1. Create a new column, set it to a Date format, and use the following formula 

   =((((THE_EPOCH_TIME/1000)/60)/60)/24)+DATE(1970,1,1)