BuildTime.cs

public static DateTime GetLinkerTime(this Assembly assembly, TimeZoneInfo target = null)
{
    var filePath = assembly.Location;
    const int c_PeHeaderOffset = 60;
    const int c_LinkerTimestampOffset = 8;

    var buffer = new byte[2048];

    using (var stream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
        stream.Read(buffer, 0, 2048);

    var offset = BitConverter.ToInt32(buffer, c_PeHeaderOffset);
    var secondsSince1970 = BitConverter.ToInt32(buffer, offset + c_LinkerTimestampOffset);
    var epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

    var linkTimeUtc = epoch.AddSeconds(secondsSince1970);

    var tz = target ?? TimeZoneInfo.Local;
    var localTime = TimeZoneInfo.ConvertTimeFromUtc(linkTimeUtc, tz);

    return localTime;
}

var linkTimeLocal = Assembly.GetExecutingAssembly().GetLinkerTime();