Why do folks think that China has a specific deadline in mind? To set a particular year/date with one's personal interests in mind could tremendously compromsie the prospects of such an operation succeeding.
China doesn't have a date, but Xi (and importantly, his coalition) has a date. The timeline isn't a military one but a political one.
Armed reunification takes tremendous political will and consolidating power in the CCP can often take years for the paramount leader. Because of how much power Xi has right now, how the transition will go remains to be seen and I think the state of politics for his successor has much more uncertainty than what members here might assume.
Also, I hold the opinion that China is at a time when overseas military influence needs to be expanded, but yet is vastly lagging behind its actual capabilities, and the Taiwan issue is a major contributing factor.