Can be predicted, but no exact date can be given. The Bitcoin protocol initiates a halving event on the Bitcoin blockchain when the number of blocks on the chain reaches 210,000 (approximately every four years).

When the number of blocks halves, the Bitcoin protocol automatically prepares for a new halving. Therefore, as the number of blocks on the blockchain increases, this date can be predicted with a high degree of accuracy.

Currently (as of 2023), the next Bitcoin halving can be expected to take place around May 2024. However, this date may change depending on the number of blocks on the blockchain.