Convert the timezone of timestamps in multiple mp3 recording files and organize them into folders based on the day number

change-timezone-and-rename.mjs

#!/usr/bin/env zx

const tz = new Date().toLocaleString("en", { timeZoneName: "short" }).split(" ").pop();

const listOfMp3Files = (await $`ls *.mp3`).stdout.split("\n").filter(Boolean);

for (const filename of listOfMp3Files) {
  let year = filename.slice(0, 4);
  let month = filename.slice(4, 6);
  let day = filename.slice(6, 8);
  let hour = filename.slice(9, 11);
  let minute = filename.slice(11, 13);
  let second = filename.slice(13, 15);
  let timestamp = new Date(`${year}-${month}-${day} ${hour}:${minute}:${second} ${tz}`);

  const date = timestamp.toLocaleDateString("en-US", {
    timeZone: "UTC",
    hour12: false,
    year: "numeric",
    month: "2-digit",
    day: "2-digit",
  });
  const time = timestamp.toLocaleTimeString("en-US", {
    timeZone: "UTC",
    hour12: false,
    hour: "2-digit",
    minute: "2-digit",
    second: "2-digit",
  });

  day = date.split("/")[1];
  hour = time.split(":")[0];
  minute = time.split(":")[1];

  // create folder with the name of the day, if found then ignore
  await $`mkdir -p ${day}`;

  // move the file to the folder
  await $`mv ${filename} ${day}/${hour}.${minute}.mp3`;
}