https://stackoverflow.com/a/1767090

// <major version>.<minor version>.<build number>.<revision>
var buildNumber = 7706;
var revision = 17812;

var result = new DateTime(2000, 1, 1);
result = result.AddDays(buildNumber);
result = result.AddSeconds(revision * 2);
Console.WriteLine($"{result:u}");
// 2021-02-05 09:53:44Z