DateTime currentTime = DateTime.Now; int unixTimestamp = (int)(currentTime.Subtract(new DateTime(1970, 1, 1))).TotalSeconds;In this example, we first get the current date and time using the DateTime.Now method. We then create a Unix timestamp by subtracting the Unix epoch (January 1, 1970) from the current time, converting the result to total seconds using the TotalSeconds property. Determining the package library for this feature is not necessary as it is a built-in feature in the System namespace of C#.