This one uses an iframe with content served externally

On this embedded calendar, the header rows (or at least the last one depending on browser) do not line up with the data rows.

calendar

This is the same but with source displayed. Trying to work out how to put this into an iframe (or alternative solution)

<link href='https://www.planyo.com/libs/fullcalendar-scheduler/lib/fullcalendar.min.css' rel='stylesheet' /><link href='https://www.planyo.com/libs/fullcalendar-scheduler/scheduler.min.css' rel='stylesheet' /><div id='cpcal_planyonet' class='cp_calendar cp_units_30 ' ></div><a title='Calendar powered by Planyo' alt='Calendar powered by Planyo' href='http://www.planyo.net' target='_blank' class='cp_pb'>calendar </a><div id='cp_fetch_cpcal_planyonet' class='cp_fetching' style='position:absolute;left:200px;top:10px;display:none;z-index:999;'><img src='https://www.planyo.com/images/hourglass.gif' /></div><script>
  if(!document.cp_instances) document.cp_instances = new Array(); document.cp_instances.push({'all_views':'custDay', 'def_view':'custDay', 'time_unit':30, 'resources':[{"id":"Main_Hall","title":"Main Hall","granulation":"30","click_url":null},{"id":"Jubilee_Lounge","title":"Jubilee Lounge","granulation":"30","click_url":null},{"id":"Linton_Room","title":"Linton Room","granulation":"30","click_url":null}],  'jsonp_url':{url:"https://www.planyo.net/fetch-calendar.php?eh=59bd452ad0b916e1a0bc6be8e8a94790d6400adc&ih=352e9ac99b5a811eef83e93fc8599eed78106fda&callback=?", cache: false}, 'timezone':'site', 'tz_offset': 0, 'min_hour':'9:00:00', 'max_hour':'23:30:00', 'open_frame':"_top", 'element_id':'cpcal_planyonet', 'fetching_id':'cp_fetch_cpcal_planyonet', 'lng': 'en'}); document.cp_time_format='HH:mm'; document.cp_title_format='dddd, MMMM Do, YYYY'; document.cp_title_format_short='ddd, MMM Do'; document.cp_s_day="day"; document.cp_s_days="days"; document.cp_s_vert_day="vertical day"; document.cp_s_month="month"; document.cp_s_week="week"; document.cp_s_weeks="weeks"; document.cp_s_agenda="agenda";
</script>
<script src='https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js'></script><script src='https://www.planyo.com/libs/planyonet-fc.js'></script><script src='https://www.planyo.com/embed-schedule.js'></script><link rel='stylesheet' href='https://www.planyo.com/planyonet/planyo.net.css' type='text/css' />