Functions to caste the youtube duration & youtube date to a common time & date string

functions.js

/**
 * Examples:
 * - PT1H20M5S > 01:20:05
 * - PT1H5S    > 01:00:05
 * - PT2H10M   > 02:10:00
 * - PT2M10S   > 00:02:10
 * - PT2H      > 02:00:00
 * - PT2M      > 00:02:00
 * - PT2S      > 00:00:02
 *
 * @param {string} duration 
 * @return {string}
 */
function YTDuration2TimeString( duration ) {
  let match = duration.match( /PT(\d+H)?(\d+M)?(\d+S)?/ );

  match = match.slice( 1 ).map( x => { if( x != null ) { return x.replace( /\D/, '' ); } } );

  const hours   = ( parseInt( match[ 0 ] ) || 0 );
  const minutes = ( parseInt( match[ 1 ] ) || 0 );
  const seconds = ( parseInt( match[ 2 ] ) || 0 );

  return new Date( ( hours * 3600 + minutes * 60 + seconds ) * 1000 ).toISOString().substr( 11, 8 );
}

/**
 * Example:
 * - Mon Apr 22 2019 10:07:50 GMT+0100 > 22/04/2019 10:07:50
 *
 * @param {number} ytdate
 * @return {string}
 */
function YTDate2DateString( ytdate ) {
  const f2digit = function( number ) { return isNaN( number *1 ) ? '??' : number *1 < 10 ? '0' + number : number +''; };
  const theDate = new Date( ytdate );

  let date = [ f2digit( theDate.getDate() ), f2digit( theDate.getMonth() + 1 ), f2digit( theDate.getFullYear() ) ].join( '/' );
  let time = [ f2digit( theDate.getHours() ), f2digit( theDate.getMinutes() ), f2digit( theDate.getSeconds() ) ].join( ':' );

  return `${date} ${time}`;
}