What is the 3rd and 4th value in the hardforks.cpp?

Question

I know what the first two values are. Version and then block height. But then there is a third value with nothing then the fourth value which contains a very long number, I do not know what it means.

The third value and fourth value in this:

  { 1, 1, 0, 1341378000 }

Is it seconds? What is the seconds for? What is it?

Answer 1

The third value is unused.

The fourth value is indeed seconds, and was used to display a "you need to update" message after about 6 months from that date, since Monero used to fork every six months. This warning is not removed, since it'd trigger pointlessly as we fork less often now, and without a constant schedule.