@zero65tech/indian-stock-market/src/index.js

Indian Stock Market Toolkit

import HOLIDAYS from "./build/holidays.json";
import SPECIAL_DAYS from "./build/special-days.json";

const IST_OFFSET_MILLIS = 5.5 * 60 * 60 * 1000;
const MAHURAT_DAY = "2026-11-08";

function isHoliday(date = new Date()) {
  // Normalize input date
  if (typeof date === "string") {
    date = new Date(date);
  } else if (date instanceof Date) {
    // Apply IST offset
    date = new Date(date.getTime() + IST_OFFSET_MILLIS);
  } else {
    throw new TypeError("Invalid date input");
  }

  let yyyy = date.getUTCFullYear();
  let mm = date.getUTCMonth() + 1;
  let dd = date.getUTCDate();

  // Check special days first
  if (SPECIAL_DAYS[yyyy]?.[mm]?.includes(dd)) {
    return false;
  }

  // Check if weekend (Saturday=6, Sunday=0)
  const dayOfWeek = date.getUTCDay();
  if (dayOfWeek === 0 || dayOfWeek === 6) {
    return true;
  }

  // Check if holiday
  return HOLIDAYS[yyyy]?.[mm]?.includes(dd) ?? false;
}

function isOpen(date = new Date()) {
  if (isHoliday(date)) {
    return false;
  }

  // Apply IST offset
  date = new Date(date.getTime() + IST_OFFSET_MILLIS);

  const dateStr = `${date.getUTCFullYear()}-${String(date.getUTCMonth() + 1).padStart(2, "0")}-${String(date.getUTCDate()).padStart(2, "0")}`;
  const hours = date.getUTCHours() + date.getUTCMinutes() / 60 + date.getUTCSeconds() / 3600;
  if (dateStr === MAHURAT_DAY) {
    return hours >= 18 && hours < 19.25;
  } else {
    return hours >= 9 && hours < 15.5;
  }
}

// TODO

const specialday = new Date(MAHURAT_DAY).getTime() / 1000 / 60 / 60 / 24; // UTC

function _istDayAndHr(date) {
  let hrs = date.getTime() / 1000 / 60 / 60 + 5.5;
  return [Math.floor(hrs / 24), hrs % 24];
}

function eq(name) {
  const match = name.match(/^(.*?)-([A-Z]{1,2})$/);
  return match
    ? { symbol: match[1], scrip: match[1], series: match[2] }
    : { symbol: name, scrip: name, series: null };
}

function monthlyExpiry(yy, mon, weekday) {
  const yyyy = 2000 + parseInt(yy);
  const mm = [
    "JAN",
    "FEB",
    "MAR",
    "APR",
    "MAY",
    "JUN",
    "JUL",
    "AUG",
    "SEP",
    "OCT",
    "NOV",
    "DEC",
  ].indexOf(mon);
  let dd = new Date(yyyy, mm + 1, 0).getDate(); // Last day of the month

  while (new Date(yyyy, mm, dd).getDay() != weekday) dd--;

  for (; dd >= 1; dd--) {
    const date = `${yyyy}-${String(mm + 1).padStart(2, "0")}-${String(dd).padStart(2, "0")}`;
    if (
      HOLIDAYS[yyyy] === undefined ||
      HOLIDAYS[yyyy][mm + 1] === undefined ||
      !HOLIDAYS[yyyy][mm + 1].includes(dd)
    )
      return date;
  }
}

function weeklyExpiry(yy, m, dd) {
  const year = "20" + yy;
  const mm = ["1", "2", "3", "4", "5", "6", "7", "8", "9", "O", "N", "D"].indexOf(m);
  return `${year}-${String(mm + 1).padStart(2, "0")}-${dd}`;
}

function info(symbol) {
  console.warn(".info() is deprecated. Use .fo() instead.");

  // FUT - Monthly Expiry (only)

  let match = symbol.match(/^(\S+?)(\d{2})([A-Z]{3})FUT$/);
  if (match) {
    let script = match[1];
    let expiry = monthlyExpiry(match[2], match[3], script == "FINNIFTY" ? 2 : 4);
    return { script, exp: match[2] + match[3], expiry, type: "FUT" };
  }

  // OPT - Monthly Expiry

  match = symbol.match(/^(\S+?)(\d{2})([A-Z]{3})([\d.]+)(PE|CE)$/);
  if (match) {
    let script = match[1];
    let expiry = monthlyExpiry(match[2], match[3], script == "FINNIFTY" ? 2 : 4);
    return {
      script,
      exp: match[2] + match[3],
      expiry,
      strike: parseFloat(match[4]),
      type: match[5],
    };
  }

  // OPT - Weekly Expiry

  match = symbol.match(/^(NIFTY|BANKNIFTY|FINNIFTY)(\d{2})(\w{1})(\d{2})([\d.]+)(PE|CE)$/);
  if (match) {
    let script = match[1];
    let expiry = weeklyExpiry(match[2], match[3], match[4]);
    return {
      script,
      exp: match[2] + match[3] + match[4],
      expiry,
      strike: parseFloat(match[5]),
      type: match[6],
    };
  }

  // MF & EQ

  return { script: symbol };
}

function fo(name) {
  // FUT - Monthly Expiry (only)

  let match = name.match(/^(\S+?)(\d{2})([A-Z]{3})FUT$/);
  if (match) {
    let scrip = match[1];
    let expiry = monthlyExpiry(match[2], match[3], scrip == "FINNIFTY" ? 2 : 4);
    return { symbol: scrip, scrip, exp: match[2] + match[3], expiry, type: "FUT" };
  }

  // OPT - Monthly Expiry

  match = name.match(/^(\S+?)(\d{2})([A-Z]{3})([\d.]+)(PE|CE)$/);
  if (match) {
    let scrip = match[1];
    let expiry = monthlyExpiry(match[2], match[3], scrip == "FINNIFTY" ? 2 : 4);
    return {
      symbol: scrip,
      scrip,
      exp: match[2] + match[3],
      expiry,
      strike: parseFloat(match[4]),
      type: match[5],
    };
  }

  // OPT - Weekly Expiry

  match = name.match(/^(NIFTY|BANKNIFTY|FINNIFTY)(\d{2})(\w{1})(\d{2})([\d.]+)(PE|CE)$/);
  if (match) {
    let scrip = match[1];
    let expiry = weeklyExpiry(match[2], match[3], match[4]);
    return {
      symbol: scrip,
      scrip,
      exp: match[2] + match[3] + match[4],
      expiry,
      strike: parseFloat(match[5]),
      type: match[6],
    };
  }

  return null;
}

function hasOpened() {
  console.warn(".hasOpened() is deprecated. Shall be removed eventually.");

  let date = new Date();
  if (isHoliday(date)) return false;

  let [day, hrs] = _istDayAndHr(date);
  if (day == specialday) return hrs >= 18;
  else return hrs >= 9;
}

function hasClosed() {
  console.warn(".hasClosed() is deprecated. Shall be removed eventually.");

  let date = new Date();
  if (isHoliday(date)) return false;

  let [day, hrs] = _istDayAndHr(date);
  if (day === specialday) return hrs >= 19.25;
  else return hrs >= 15.5;
}

export default { eq, info, fo, isOpen, hasOpened, hasClosed, isHoliday };

export { isHoliday as isISMHoliday, isOpen as isISMOpen };