BIP65 CHECKLOCKTIMEVERIFY

@gmaxwell As discussed.
For proof-of-sacrifice you want the txout to be locked for months if not years to get past miner business cycles. I'm not worried about a transaction being censored when the timeframes are that long.

Anyway, a future BIP can define a CHECK-BLOCKHEIGHT-VERIFY opcode that leaves a block height on the stack, which could be used in conjunction with ADD to do what you want. But that's a heck of a lot of complexity right now for a very niche use-case.