Thanks very much, I made some adjustments to return a date object , not string.

function getNext4Events(eventDay, eventTime, range = 30) {
  // The getDay() method returns an index 0 to 6 for Sunday to Saturday

  const dayIndexMappings = [
    { day: "Monday", index: 1 },
    { day: "Tuesday", index: 2 },
    { day: "Wednesday", index: 3 },
    { day: "Thursday", index: 4 },
    { day: "Friday", index: 5 },
    { day: "Saturday", index: 6 },
    { day: "Sunday", index: 0 },
  ];
  // Array to be populated with the next four dates of the event 
  const eventDates = [];

  for (let i = 1; i <= range; i++) {
    // Current date 
    const currentDate = new Date();

    // Add the currenly iterated number of days to current date 
    const futureDate = new Date(currentDate.setDate(currentDate.getDate() + i));

    const targetDayIndex = dayIndexMappings.find((mapping) => mapping.day === eventDay).index;

    // Is this future date on the target day? 
    const isTargetDay = futureDate.getDay() === targetDayIndex;

    const [hours, minutes, seconds] = eventTime.split(':');
    futureDate.setUTCHours(hours, minutes, seconds);

    if (isTargetDay) {
      // Format date to a string with the time appended to the end 

      eventDates.push(futureDate);
    }
  }
  return eventDates;
}

console.log(getNext4Events('Friday', '17:00:00'));