Index / Trading days

pattern · MIT · last updated 2026-08-27

Trading days

Revert beforeSwap outside NY weekday cash hours (9:30–16:00 ET, fixed UTC-5).

First-party rewrite inspired by horsefacts trading-days (MIT). beforeSwap reverts on weekends or outside the cash session. First open swap of the day emits DingDingDing. Simplified vs the original: no holiday/DST libraries — weekday + hour gate only. 14 permission fields, OpenZeppelin BaseHook. Listing is not an audit. Forge tests under test/TradingDays.t.sol.

Permission bits

These bits must match the deployed address. Confirm on-chain before you route.

beforeSwap

Solidity

Excerpt from contracts/TradingDays.sol. Copy the full file to implement this. Not an audit.

function getHookPermissions() public pure override returns (Hooks.Permissions memory) {
    return Hooks.Permissions({
        beforeInitialize: false,
        afterInitialize: false,
        beforeAddLiquidity: false,
        afterAddLiquidity: false,
        beforeRemoveLiquidity: false,
        afterRemoveLiquidity: false,
        beforeSwap: true,
        afterSwap: false,
        beforeDonate: false,
        afterDonate: false,
        beforeSwapReturnDelta: false,
        afterSwapReturnDelta: false,
        afterAddLiquidityReturnDelta: false,
        afterRemoveLiquidityReturnDelta: false
    });
}

Spec

FAQ

Can I paste this into production? The snippet is an excerpt. Use the full file at the source URL, match flags to the address, and treat this page as a map, not a guarantee.

How do I build this safely? Start with secure v4 hooks and the OpenZeppelin hooks guide.