AspIW_TimeCalc.js

var data = [];
var current_year = (new Date()).getFullYear();
var $rows = document.querySelectorAll('table.rpt>tbody>tr');
var node = document.createElement( 'td' );
node.innerHTML = '<div>Work Period</div>';
$rows[0].appendChild( node );

node = document.createElement( 'td' );
node.innerHTML = '<div>Work Day</div>';
$rows[0].appendChild( node );

for(var i = 1; i < $rows.length; i++) {
  var $row = $rows[i];
  var $period = document.createElement('td');
  var $day = document.createElement('td');
  var entry = {
    $row: $row,
    $status: $row.cells[1].children[0],
    $date: $row.cells[2].children[0],
    $notes: $row.cells[3].children[0],
    $period,
    $day,
    status: $row.cells[1].children[0].textContent,
    date: new Date($row.cells[2].children[0].textContent),
    notes: $row.cells[3].children[0].textContent,
    period: undefined,
    day: undefined,
  };

  $row.appendChild($period);
  $row.appendChild($day);

  // if(entry.date.getFullYear() < current_year - 1)
  //   break;
  
  var adjustment = entry.notes.match(/\s*@?(?:(\d\d?)(?::(\d\d))?)\s*(A\.?M\.?|P\.?M\.?)?\s*(?:(\d\d?)\/(\d\d?)(?:\/(\d\d?\d?\d?))?)?/i);

  if(adjustment != null) {
    if(entry.notes.length > adjustment[0].length + 2) {
      entry.$date.style.color = 'red';
      continue;
    }

    if(adjustment[4]) {
      var year = adjustment[6] ? parseInt(adjustment[6].padStart(4, '20')) : entry.date.getFullYear();

      entry.date.setFullYear(year, parseInt(adjustment[4]) - 1, parseInt(adjustment[5]));
    }

    var hours = parseInt(adjustment[1]);

    if(hours <= 12) {
      if(adjustment[3])
        hours += adjustment[3].toUpperCase().replaceAll('.','') == 'PM' ? 12 : 0;
      else if(entry.date.getHours() > 12)
        hours += 12;
    }

    if(adjustment[2])
      entry.date.setHours(hours, parseInt(adjustment[2]), 0);
    else
      entry.date.setHours(hours, 0, 0);
    
    entry.$date.style.color = 'cyan';
    entry.$date.setAttribute('title', `Adjusted from ${entry.$date.textContent}`);
    entry.$date.style.cursor = 'pointer';
    entry.$date.innerHTML = `${entry.date.getFullYear()}-${(entry.date.getMonth() + 1).toString().padStart(2, '0')}-${entry.date.getDate().toString().padStart(2, '0')} ${entry.date.toLocaleTimeString('en-GB')}`;
  }

  data.push(entry);
}

var last_in;
var last_day;
var day_hours = 0;

for(var i = data.length - 1; i >= 0; i--) {
  var entry = data[i];

  switch(entry.status) {
    case 'IN':
      last_in = entry.date;

      if(entry.date.getDate() != last_day)
        last_day = entry.date.getDate();

      break;
    case 'OUT':
    case 'LUNCH':
      if(!last_in) continue;

      entry.period = Math.round((entry.date - last_in) / 36000) / 100;
      entry.$period.innerHTML = `<div>${Math.floor(entry.period)}:${Math.round((entry.period % 1) * 60).toString().padStart(2, '0')}</div>`;

      last_in = undefined;
      day_hours += entry.period;

      if(!data[i-1] || data[i - 1] && data[i - 1].date.getDate() != entry.date.getDate()) {
        entry.$day.style['text-align'] = 'right';
        entry.$day.innerHTML = `<div>${entry.date.toLocaleDateString('en-US')}: ${Math.floor(day_hours)}:${Math.ceil((day_hours % 1) * 60).toString().padStart(2, '0')}</div>`;
        day_hours = 0;
      }

      break;
  }
}

bookmarklet.js

javascript:(() => {var script = document.createElement('script'); script.type = 'text/javascript'; script.src = 'https://gist.githack.com/bosconian-dynamics/0cf0414cdbaa63522404630f96c7b24b/raw/AspIW_TimeCalc.js'; document.body.appendChild(script);})();