The length of a mead fermentation can vary (nutrient levels, ph, temperature, yeast strain, etc), but you should be able to do it in 30 days. Then, rack to a secondary for it to age and clarify. I would age it in the carboy as long as possible, but you can bottle it as soon as it clarifies if you need the carboy. Some of my meads clarify quicker than others. A few months is probably typical.