code: func Zone(loc *time.Location) (string, int64) {
  	_, offset := time.Now().In(loc).Zone()
  	name := loc.String()
  	// when we found name is "System", we have no chice but push down
  	// "System" to tikv side.
  	if name == "Local" {
  		name = "System"
  	}
  
  	return name, int64(offset)
  }
docs: // Zone returns the current timezone name and timezone offset in seconds.
  // In compatible with MySQL, we change `SystemLocation` to `System`.