Zcash launched with Bitcoin's shape. The Blossom upgrade changed it at block 653,600, in October 2019 — three numbers at once:
Twice as many blocks, each worth half as much, and twice as far to the next halving. The ZEC paid out per day did not change, and neither did the calendar the supply arrives on. Only the block numbers did.
That is why the first halving landed at block 1,046,400 (18 November 2020) rather than 840,000, and it is the detail most halving countdowns get wrong: assume 840,000 and the dates come out years off. The schedule below is computed from the post-Blossom interval and checked against the heights the network actually halved at.
| # | Block | Reward after | Status |
|---|---|---|---|
| 1 | 1,046,400 | 3.12500 ZEC | done |
| 2 | 2,726,400 | 1.56250 ZEC | done |
| 3 | 4,406,400 | 0.78125 ZEC | projected |
| 4 | 6,086,400 | 0.39062 ZEC | projected |
| 5 | 7,766,400 | 0.19531 ZEC | projected |
Future rows are projections: the block heights are fixed by consensus, but when the chain reaches them depends on real block times, which drift with hash rate. Past rows are heights the network actually reached.
Related: daily emission and inflation rate, total ZEC mined, and the deferred dev fund, which takes a share of each block reward since NU6.