select 
  task_name,
  start_date,
  end_date,
  status,
  assigned_to,
  case status
     when 'Open'    then 'apex-cal-green'
     when 'Pending' then 'apex-cal-yellow'
     when 'Closed'  then 'apex-cal-red'
     when 'On-Hold' then 'apex-cal-black'
  end as css_class
from 
  eba_ut_chart_tasks