Date#strftime for Prototype

Prototype - Date#strftime

Date.monthNames = [
  'January', 'February', 'March', 'April', 'May', 'June', 'July',
  'August', 'September', 'October', 'November', 'December'
];

Date.dayNames = [
  'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday',
  'Saturday'
];

Object.extend(Date.prototype,
  {
    strftime: function(format)
    {
      var syntax     = /(^|.|\r|\n)(%([A-Za-z]{1,2}))/,
          components = {
            a:  Date.dayNames[this.getDay()].substring(0, 3),
            A:  Date.dayNames[this.getDay()],
            b:  Date.monthNames[this.getMonth()].substring(0, 3),
            B:  Date.monthNames[this.getMonth()],
            d:  this.getDate(),
            dd: this.getDate().toPaddedString(2),
            H:  this.getHours() % 12 || 12,
            HH: (this.getHours() % 12 || 12).toPaddedString(2),
            I:  this.getHours().toPaddedString(2),
            m:  this.getMonth(),
            mm: this.getMonth().toPaddedString(2),
            M:  this.getMinutes(),
            MM: this.getMinutes().toPaddedString(2),
            p:  this.getHours() >= 12 ? 'PM' : 'AM',
            S:  this.getSeconds(),
            SS: this.getSeconds().toPaddedString(2),
            w:  this.getDay(),
            y:  this.getFullYear().toString().substring(2, 4),
            Y:  this.getFullYear()
          };
      return format.interpolate(components, syntax);
    }
  }
);