Root.getTimeZone ()
function returns the (already cached) TimeZone-Object

Sourcecode in Root/objectFunctions.js:
1:   function getTimeZone() {
2:      if (this.cache.timezone)
3:          return this.cache.timezone;
4:      if (this.sys_timezone)
5:          this.cache.timezone = java.util.TimeZone.getTimeZone(this.sys_timezone);
6:      else
7:          this.cache.timezone = java.util.TimeZone.getDefault();
8:      return this.cache.timezone;
9:   }