leporello-js/docs/examples/ethers/block_by_timestamp.js

import { ethers } from "ethers"

const URL = "https://eth-mainnet.public.blastapi.io"

const provider = await ethers.getDefaultProvider(URL)

const latest = await provider.getBlock("latest")

/*
  Find ethereum block by timestamp using binary search
*/
async function getBlockNumberByTimestamp(
  timestamp,
  low = 0,
  high = latest.number,
) {
  if (low + 1 == high) {
    return low
  } else {
    const mid = Math.floor((low + high) / 2)
    const midBlock = await provider.getBlock(mid)
    if (midBlock.timestamp > timestamp) {
      return getBlockNumberByTimestamp(timestamp, low, mid)
    } else {
      return getBlockNumberByTimestamp(timestamp, mid, high)
    }
  }
}

const timestamp = new Date("2019-06-01").getTime() / 1000
const blockNumber = await getBlockNumberByTimestamp(timestamp)
const block = await provider.getBlock(blockNumber)