The best tide depends on location. The most important part of the tide is usually the current. If the water is flowing, incoming tide in someplaces, outgoing in another, or sometimes both, fish become active and feed. The same goes for squid. Night time is definately a plus.
If looking for squid you could start now. Lights are usually required to attract the majority of squid to your spot. But they are around in the dark too, a bit harder to catch though. You can set up your own light, but it's easier to poke around in places where there is a permenant light. A street light, bridge lights, dock lights, etc. Or some other nice guy who has set up a light and is willing to share with you (good luck with that one

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Moving water is key. Good luck!