alirussell

function lastSunday(month, year) {
  var d = new Date();
  var lastDayOfMonth = new Date(Date.UTC(year || d.getFullYear(), month+1, 0));
  var day = lastDayOfMonth.getDay();
  return new Date(Date.UTC(lastDayOfMonth.getFullYear(), lastDayOfMonth.getMonth(), lastDayOfMonth.getDate() - day));
}

function isBST(date) {
  var d = date || new Date();
  var starts = lastSunday(2, d.getFullYear());