Formatting a Date Object Based on a Dynamic Pattern

To create a function that takes a Date object and a date format pattern from a variable (such as M/D/YYYY) and returns the date formatted according to that pattern, we can implement a custom formatting function. This will dynamically format the date based on the pattern provided in the variable.

function formatCustomDate(date, formatPattern) {

  // Extract the components of the date

  let day = date.getDate();

  let month = date.getMonth() + 1; // getMonth() is zero-based, so add 1

  let year = date.getFullYear();

  let hours = date.getHours();

  let minutes = date.getMinutes();

  let seconds = date.getSeconds();

  // Ensure all components are two digits if needed (e.g., 01, 02)

  day = day < 10 ? ‘0’ + day : day;

  month = month < 10 ? ‘0’ + month : month;

  hours = hours < 10 ? ‘0’ + hours : hours;

  minutes = minutes < 10 ? ‘0’ + minutes : minutes;

  seconds = seconds < 10 ? ‘0’ + seconds : seconds;

  // Replace tokens in the format pattern with actual date components

  let formattedDate = formatPattern

    .replace(‘DD’, day)     // Day

    .replace(‘D’, day)      // Single-digit day (if format doesn’t want leading zeros)

    .replace(‘MM’, month)    // Month

    .replace(‘M’, month)     // Single-digit month

    .replace(‘YYYY’, year)    // Full year

    .replace(‘YY’, year.toString().substr(2, 2)) // Last two digits of year

    .replace(‘HH’, hours)    // Hours (24-hour format)

    .replace(‘mm’, minutes)   // Minutes

    .replace(‘ss’, seconds);   // Seconds

  return formattedDate;

}

// Example usage:

let currentDate = new Date();

let dateFormat = ‘M/D/YYYY’; // This can come from a variable

let formattedDate = formatCustomDate(currentDate, dateFormat);

log.debug(‘Formatted Date:’, formattedDate); // Expected output: e.g., “10/16/2024”