The Bitcoin difficulty adjustment mechanism typically occurs every 2016 blocks, which corresponds to roughly every two weeks. This process is designed to maintain an average block creation time of about 10 minutes, regardless of the total mining power in the network. After every 2016 blocks are mined, the network evaluates the time it took to mine those blocks and adjusts the mining difficulty accordingly: if blocks were found faster than the 10-minute target, difficulty increases; if slower, difficulty decreases. This automatic recalibration ensures Bitcoin's long-term supply predictability and network security.