What is problem? Assets/classs.cs(14,10): error CS0131: The left-hand side of an assignment must be a variable, a property or an indexer

using System.Collections; using System.Collections.Generic; using UnityEngine; public class classs : MonoBehaviour { public GameObject light; TOD_Sky ts; // this is script public int time=19; void Start () { if (ts.Cycle.Hour < time) { light.SetActive = true; } } // Update is called once per frame void Update () { } }