Bitcoin is the world's first decentralized digital currency. The rate at which bitcoins enter circulation is cut in half every 4 years, approximately. These events are considered landmarks in Bitcoin's history, and as such are widely celebrated. However, this requires placing confidence intervals on the precise timing of the halving well in advance, and the particular mechanism by which the halving time is determined makes this challenging. In this paper, we intend to help party planners by describing the problem, and highlighting several techniques to estimate the mean and variance of the halving.