samynathanv-npm-package/index.js

A simple npm package

// index.js
// Function to convert IST (Indian Standard Time) to Eastern Time (ET)
function convertISTtoET(istTime) {
    // IST is UTC +5:30, ET is either UTC -5 (EST) or UTC -4 (EDT)
    
    // Split the input IST time into date and time components
    const [date, time] = istTime.split(' ');
    const [year, month, day] = date.split('-');
    const [hour, minute, second] = time.split(':');

    // Create a Date object for IST (UTC +5:30)
    const istDate = new Date(Date.UTC(year, month - 1, day, hour - 5, minute - 30, second));

    // Convert the IST Date object to UTC and then to Eastern Time (ET)
    const utcDate = new Date(istDate.toUTCString());
    
    // Get the current date to check for daylight saving time
    const currentDate = new Date();

    // Determine if the current date is in Daylight Saving Time (DST) in the Eastern Time Zone
    const isDST = currentDate.toLocaleString('en-US', { timeZone: 'America/New_York' }).includes("PM");

    // Adjust UTC to Eastern Standard Time (EST or UTC -5) or Eastern Daylight Time (EDT or UTC -4)
    let etDate;
    if (isDST) {
        // Eastern Daylight Time (EDT)
        etDate = new Date(utcDate.setHours(utcDate.getHours() - 4));
    } else {
        // Eastern Standard Time (EST)
        etDate = new Date(utcDate.setHours(utcDate.getHours() - 5));
    }

    // Return the formatted ET time in 'YYYY-MM-DD HH:mm:ss' format
    const formattedET = `${etDate.getUTCFullYear()}-${String(etDate.getUTCMonth() + 1).padStart(2, '0')}-${String(etDate.getUTCDate()).padStart(2, '0')} ${String(etDate.getUTCHours()).padStart(2, '0')}:${String(etDate.getUTCMinutes()).padStart(2, '0')}:${String(etDate.getUTCSeconds()).padStart(2, '0')}`;
    
    return formattedET;
}

// Export the function for use in other files
module.exports = { convertISTtoET };