How long does it take to build a 20-story house?

What I learned from professionals: construction process: I forgot to ask the time of trenching-piling-masonry, which should not be too long; The main time of construction is wasted on piling. The two-unit building needs about 482 piles, each with a diameter of 40cm and a length of16.7m.. It will take ten days to finish the 482 piles, and then it will take more than 20 days to maintain them, and it will take one month. Then Gai Lou, the first floor will be completed in seven or eight days. In this case, in theory, a 20-story building will take about 6 months to build. However, in the actual operation process, various approval procedures and various weather restrictions will be encountered, resulting in different actual time.