Will bud be out of my system in less than 28 days?

First of all please don't buy that 30 day bullshit. You can smoke for YEARS and be clean in under 28 days, as long as you work out, eat LOTS of food (healthy) and DON'T smoke.
 
First you need to start working out. Cardio along with weights will help. Start eating lots of healthy meals. You want to be shitting a lot since 75% of THC is excreted through the stool. Second of all drink around 1/2-3/4 of a gallon of water day. Don't water board yourself but drink lots of water to keep your system fully hydrated. DON'T chug a gallon every day, just keep yourself very hydrated because you will also be busting ass at the gym. 
 
Since you are obviously a very chronic smoker it will all depend on how hard YOU work. You can absolutely be 100% clean in 26 days if you work out HARD, eat right and abstain from toking. 
 
On the day of the test drink lots of water and a diuretic (coffee,tea,etc). At home tests are a joke as they don't test for gravity, temp, creatine,etc. 
 
If you want to be a dumbass get some Quick Fix (synthetic urine) and you will pass with flying colors, assuming you're parents aren't faggots and watch your dick when you pee.
 
A lot of people use Quick Fix for pre employment screens because they *can't* watch you piss. 
 
All in all, as long as you make a huge effort to get clean you will be okay. I've done it in less. And I've probably smoked more than you (not bragging).
 
EDIT: I recommend an hour on the stationary bike (where you sit down) and bust out an hour on the Hill Climb program. When you do cardio you want the intensity (the actual setting on the machine) to be pretty high, you will feel your legs turn to jello.
 
I usually do weights first (stick with Bench, Squats, Deadlifts) and then do cardio. You will want to stick with full body exercises because that burns the most fat/calories, and THC is stored in nothing but your fat. Stick to Dead Lifts, Squats, Leg Press, Bench Press, Military Press/Hang Cleans, and basically any workout that stimulates your ENTIRE body. Ever done HEAVY squats or dead lifts? Every muscle feels it. 
 
Don't do isolation exercises like bicep curls or anything with abs really. You want to do compound exercises that works multiple muscle groups at the same time. Look it up if you don't know any but the ones I listed are more than enough if you lift ***HARD***
 
EDIT2 (lol): Also you want to hit your legs HARD because they release a chemical that promotes fat burning by up to 10-20% so hit legs almost everyday, granted you are eating massive amounts of food (as you should).
 
When you eat less your body initially conserves calories and fat and you do the exact OPPOSITE of what you want, your body keeps the THC. The more food you push through your body the more THC goes out. I'm not sure if it's 75% of THC is excreted through the stool, but it's definitely a high percentage.

 

I bet it'll be less than 2 weeks

 

Okay if that's the case then go buy some protein powder and creatine powder. Start taking those regularly. Beware with the creatine though, if you don't work out enough the creatine doesn't get processed and you have mad shits. You will know if you are working out hard enough if you feel okay after taking a bunch of creatine and protein powder. 
 
On the day of the test, a few hours before, get a gatorade (big bottle) and start drinking it at a moderate pace. Keep pissing for a few hours every now and then (don't kill yourself) and also piss in a clear cup before you piss in the toilet. The reason I say this is because in the toilet piss looks very clear and you think you are good but then when you actually pee in a cup you can definitely see how concentrated it is. You want it to be pale yellow/almost white. Do not worry about color at all because if all levels are good (gravity, creatine,temp etc) they can't fail you for color alone. If your piss isn't close to clear normally then you aren't drinking enough water (Even if you don't have to take a drug test). 
 
Gravity: Gatorade will help with the gravity levels (because you will be diluting this even if you are clean).
Creatine: Creatine powder along with working out will keep your levels normal even if the rest of your piss is clear/diluted.
Temp: Just piss in a cup lol.
 
I forget what else they test for but these should be the main things that help you pass.
 
The reason I say you want to try to dilute it (even if you are clean) is because you always want to be safe. A dilution is NOT a fail, it just means they couldn't get an accurate result. It means there could or could not be drugs in your system, but they don't know because you never gave them actual piss (you diluted it down so the drugs in your system would be below the detectable level).
 
Dilution is like an art almost lol. Takes time and practice.

 

you're fine. if you're living with parents and they're buying you a car. What is that car worth to you? I've never had that opportunity. I recommend staying clean until you're an adult (physically, mentally, and financially). Good on you for doing your research. Just stay clean, focused and do you. You could go which ever way you wanted with this. It's all attitude and drive. You can be a stoner and succeed and you can not and succeed as well. I'm assuming you're over the age of 18 as you're on here and I have known college kids to stay at home and do their thing and get some assistance from the 'rents. If that's the case, respect them. now that all the mentor crap is out of the way, yes you can easily be clean in under 28 days. Exercise, diet and motivation will determine how quickly you can pass. also things like metabolism, weight and fat content matter hugely.