static DateTime GetDTCTime(ulong nanoseconds, ulong ticksPerNanosecond)
{
    DateTime pointOfReference = new DateTime(2000, 1, 1, 0, 0, 0, DateTimeKind.Utc);
    long ticks = (long)(nanoseconds / ticksPerNanosecond);
    return pointOfReference.AddTicks(ticks);
}

static DateTime GetDTCTime(ulong nanoseconds)
{
    return GetDTCTime(nanoseconds, 100);
}