如何使用 getBlockTime

# Replace SLOT_NUMBER_TO_QUERY with a valid slot, e.g., a recent one from an explorer
curl https://mainnet.helius-rpc.com/?api-key=<api-key> -X POST -H "Content-Type: application/json" -d \
  '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getBlockTime",
    "params": [
      SLOT_NUMBER_TO_QUERY 
    ]
  }'

const { Connection } = require('@solana/web3.js');

async function getSpecificBlockTime(slotToQuery) {
  const connection = new Connection('https://mainnet.helius-rpc.com/?api-key=<api-key>');
  try {
    const blockTime = await connection.getBlockTime(slotToQuery);
    if (blockTime !== null) {
      console.log(`Estimated time for slot ${slotToQuery}: ${new Date(blockTime * 1000).toISOString()} (Unix: ${blockTime})`);
    } else {
      console.log(`Timestamp not available for slot ${slotToQuery}.`);
    }
  } catch (error) {
    console.error('Error fetching block time:', error);
  }
}

// Example usage: Replace with a recent, valid slot number from Mainnet Beta
// You can find recent slots on Solana explorers like Solscan or SolanaFM
const slotToQuery = 300000000; // Replace with an actual slot number
getSpecificBlockTime(slotToQuery);