I can only speak from limited personal experience and the conventional knowledge. Hopefully you’ll also receive some expert input.
As for time of year, I’d say when the water gets cold and clear, probably December-February. Using Google Earth and/or input from experienced folks, I’d look for areas with mud flats at low tide. Then I’d check the tides for that area and local sunrise times. I’d look for dead lows happening in the morning, not long after sunrise (for the first day of the trip). Haunt those mudflats starting 1 or 1.5 hours before low and look for fish through the low tide. The primary reason to choose the early morning, in my very limited experience, is because you’ll have the best chance at low wind. Local knowledge would be very nice to help you know how a flat will actually look at a specific tide, and to help you avoid getting stranded. If you go in with your light boat just before dead low, be careful and you should be OK. If you’re cautious, the worst case is you get stuck maybe 2-3 hours waiting on the tide.
G