Hi Anoop,

Good question. 
The day ratings are simply based on the moon phase and the combined gravity between moon and sun.
For example during new moon, sun and moon rise at the same time and their combined gravity, coupled with dark nights creates excellent fishing conditions... if the weather plays along.
The local weather isn't  included in that rating and must be taken into consideration separately. 

Usually if there is no bite during a good fishing time it is rather an indication that there aren't any fish in this spot or that the bait is not right.
In that case it's best to move on and try other spots.

Hope that helps 
Cheers

There is a link at the bottom of each page How It Works.

It is a combination of sun, moon, tides etc.

At the end of the day, it comes down to the person. You have to be where the fish are. Using bait or lures that the fish want. You have to use the right method. I have often stated I could toss lures into a bath tub full of water all day on the best of best days and not catch a thing !!

If you go fishing in a major time on a 4 star day and don't catch anything. Then the first thing to do is look at what you are doing or not doing. For example, about 90% of people cast straight over the top of the fish they are trying to catch. I was fishing on a beach once where the fish were in a very narrow stretch about 3 meters (10 feet) wide. Sometimes it can literally come down to inches.

A good idea is to simply cast in different spots until you find the fish. What I do, is give my first cast about 10 minutes. If nothing happens, I reel in and cast again a few feet to either side. I keep doing that until I find the fish or have covered the whole area. If nothing is happening in the area then move to a new spot.

If you notice a big difference between major and minor, it could just mean that you were in the right spot at the right time...or in the wrong spot.

The best days I had didn't happen on any major/minor bite time or an excellent rated day according to this site. Matter of fact, days was rated as poor.

Look for trends in your area and fish to it. I've been to areas where activity was good on moonrise and then died off completely as soon as the moonlight started to shine as the moon came over the hills. It was also dependant on what time of day the moonrise was. Moon over and moon under is usually dead where I fish. 

The biggest fishes i've caught are mostly caught late night. Generally, I find the day before, the day of and the day after the 4 moon phase are terrible for fishing.

There is one area I fish that is generally horrible. Persons will go a week without catching anything meaningful. From the time sprats start to run the area, then it's excitement galore. Some monster fish are usually seen running fish crazy in the area and really close to shore.

I've decided to revisit this and add more input incase newbies to fishing are still wondering about these things as I believe it's not as simple as going by the major and minor times as so many things affect fishing.

- Advice you see on the internet maybe geographic only. For example, what works in Australia may not work in the USA or Caribbean for various reasons (season, water temperature, salt or freshwater, large difference between low and high tide etc).

- Learn your spot where you fish. A specific specie of fish will behave differently depending on the area for various reasons. Example, fishing may only be hot at your spot when conditions are dirty because there is little cover otherwise for fish. Another example is fish only feeding when school of bait fish is around as there is little food otherwise that they are interested in.

- Advice can differ depending on if you fish inshore or offshore. What works offshore may not work inshore. 

- What works for one specie isn't a guarantee to work for other specie, even for sub specie. Example, what works for a mutton snapper isn't guaranteed to work for yellowtail snapper. What works for Trevally isn't a guarantee for Barracuda.

- Know the fish in your area for the following reasons:
(1) Will help you to determine what bait or lure to use. Some fish will absolutely reject dead bait on the bottom 99% of the time while some will gladly take it. If smaller fish is around, you would know to use smaller lure/bait or if big fish around bigger lure/bait.

(2) it will help you determine which time of day is best to fish. Some fish are better caught at night, some during the day.

(3) Will help determine the better moon phase. Yes different fish do behave differently according to the moon phase. Example, In my area Cero Mackerel are all about the new moon.

(4) Will help determine which of the daily solunar period is better for fishing. Some fish bite better when the moon is up, some when it's down. Some fish go incognito as soon as moonlight starts to shine (better believe it). Some are all about sunrise, sunset etc.

- Not all fish work according to the major and minor times. Example where I live, all the best catches I've had never happened during any of the major periods. Few hours after the major period is when I've landed all my inshore monsters. Fishing usually goes a little dead after moonrise and same during moonset at night. This comes back to understanding your area and the type of fish around. The incoming tide where I am at, starts usually around the major period which may explain why it's usually dead and why couple hours after is more productive as that's when you have more tidal movement. In my area, tide generally goes out around moonrise and moonset which might explain the slow period for inshore fishing.

- Nothing about fishing is constant.

- Fish has their season. Ever wondered why you catch a specie in abundance and all of a sudden nothing?

- 6 months of the year, full moon has the stronger tides while the other 6 months, the new moon takes over. (Nothing is constant)

- The water level drops for half of the year and returns the other half (nothing is constant)

- Your best fishing days will eventually always coincide with one of the new or full moon (3-4 days either side of it).

- This maybe area specific, but parts of the year, the big tides from the new or full moon can start 3 days before and go on to 2-3 days after. Some parts of the year, it starts around the day itself of the moon and last up until the day of or before the quarter moon (nothing is constant)

- Your catch will be bigger certain months of the area for different specie and some months, quite small (nothing is constant).

- The sun and moon affects the tide which is why they matter so much in fishing. The closeness and distance of the sun to earth affect the rough and calmess of the sea. 

- Sometimes, fish may occupy one area of a bay and then change to the other side. Can be because of water visibility, calmness/roughness etc.