Try days around the new moon, with high tide at dawn or dusk. Fish around this time and you should pick up squid.
If you fish these times and don't get one within a few casts, try moving around to other spots, because if they are there and hungry, they normally hit your jigs as soon as they touch the water.
The mix of a rocky outcrop and kelp bed sounds like prime squid real estate, you just need to crack that first one and you'll be on your way.
But note - if you can, don't spend 4 hrs in the one spot once a fortnight plugging away at it. Spend 30 mins each time and go more often (and try different spots), and you will get much better results.