How to rotate camera around object smoothly in fixed intervals

Basically I want the camera to rotate at 90 degree intervals upon keypress.

I have the following:

public GameObject targetObject;
	private float targetAngle = 0;
	const float rotationAmount = 1.0f;
	
	// Update is called once per frame
	void Update()
	{
		
		// Trigger functions if Rotate is requested
		if (Input.GetKeyDown(KeyCode.LeftArrow)) {
			targetAngle -= 90.0f;
		} else if (Input.GetKeyDown(KeyCode.RightArrow)) {
			targetAngle += 90.0f;
		}
		
		if(targetAngle !=0)
		{
			Rotate();
		}
	}
	
	protected void Rotate()
	{
		
		if (targetAngle>0)
		{
			transform.RotateAround(targetObject.transform.position, Vector3.up, -rotationAmount);
			targetAngle -= rotationAmount;
		}
		else if(targetAngle <0)
		{
			transform.RotateAround(targetObject.transform.position, Vector3.up, rotationAmount);
			targetAngle += rotationAmount;
		}

	}

This works fine, but my question is should I be applying Time.Deltatime at any point to ensure it happens smoothly?

Thanks.

All you have to do is multiply your rotationAmount by Time.deltaTime
Like this

transform.RotateAround(targetObject.transform.position, Vector3.up, -rotationAmount * Time.deltaTime);

You might have to make your rotationAmount a bit higher, since Time.deltaTime is usually around 0,016667