While a 30 day squat challenge is a great way to challenge yourself, you shouldn't do the same squat exercise everyday. Doing different squats target your glutes from multiple angles and shape the perfect butt.
Bruce Lee quote - If you always put limits on everything you do, physical or anything else, it will spread into your work and into your life. There are no limits. There are only plateaus, and you must not stay there, you MUST GO BEYOND THEM.