What is the quickest way to get a tan and how long does it take to get..

There is no quick way to get a tan. There are five different levels to tans that you can find here: http://animalcrossing.wikia.com/wiki/Tan

To get a tan, make sure you stand out in the sun during the daytime. It's probably best to do this on the island as it is rarely cloudy or rainy there. Remove any headgear, accessories or umbrellas as some of these prevent tanning. Your 3DS must also be left open for this to work. Each hour you spend in the sun, your skin will get darker. That means if you want your skin as dark as possible, you need to leave your 3DS for five hours.

Because I'm sure you'd rather be playing for these five hours, I recommend changing your clock to daytime when in real life it is evening so that whilst you sleep you can leave your 3DS switched on to get a tan

Like real life, getting a tan is not quick, although it does happen faster in the game than in real life.

To get a tan, you need to be outside on a warm, sunny day. Tans are easier to get in the summer. There cannot be clouds. You can do this in your town, but going to Tortimer Island guarantees the correct conditions for getting a tan. You can run around fishing, planting, and swimming if you like, or you can leave the game on and the 3DS open (not in sleep mode). It will take a few hours of being in the sun for a tan to appear. It may take multiple days to get to the darkest color. The tan will NOT appear until the next day.

You can go to the island and use the wetsuit, and stay in the water and put down the 3ds (charging is a good idea) for an hour and a half (or more) and repeat for 7 days (if you have that kind of money, if not- stay for longer for less days) (: or more if you want a darker color. ALSO! Take off all headgear socks and accessories! (knowledge from http://www.youtube.com/watch?v=bCBp-PkdJZQ )

You need to stand outside in the sun at the island or in town when it's Summer for a few hours. You can't get to the darkest stage of a tan in 1 day, it takes several days to reach that stage of tan.

I know a way that you can get marriage, tanning and babies version/mod.
You get a wedding, tan and baby parlour. You also get a church, honeymoon resort and daycare/kindy/school

Just remove everything excluding shirt and pants and charge your 3ds and leave the screen OPEN!!! Come back in 1 to 2 hours and you will usually have a tan

To get a tan is to go to the island if you have that kind of money, then you can charge and wait a while, and boom a tan! You can check if you go inside you'll be slightly decker than you were before. Also the other way to tell you have a tan is to make a shirt that's the same color as your normal skin.

The best way to get a tan is to get Kapp'n to take you to Tortimer Island. If it is raining at the island, if you don't want to do something else there then sorry about the 1,000 bells you wasted... 😩 If it isn't raining then congratulations! You are on your way to getting a tan! Anyway, when you see that it isn't raining, go and ask Lloyd for a wetsuit, or just use yours if you were wearing it! Then go to the corner of the ocean (any corner will do) and leave your 3DS there for at least an hour. WARNING: DO NOT CLOSE IT! It is recommended that you keep it on charge at this point. Then save and quit. The next day/the next time you load up you will have a tan! The more hours you stayed there, the darker tan you will have. If you can't see your tan, then create a skin coloured design. Wear it as a shirt! Done!

Since the Welcome Amiibo update, the quickest way to get a tan is actually by wearing a mii mask with darker skin than your character's. Other than that, use the methods above.

There is 7 colours of tan you can get. Between July 16th to September 15th, go outside on a cloudless day for 15 mins or longer. It will take a while to get the darkest. Also, if it rains, your tan will begin to disappear. If you need to top up your tan in any other month to to the island. The key thing is that you don't wear any headgear whatsoever, no flowers, glasses, hats or masks.
I hope you find this useful!