Mathf.MoveTowardsAngle
static function MoveTowardsAngle(current: float, target: float, maxDelta: float): float;
static float MoveTowardsAngle(float current, float target, float maxDelta);
static def MoveTowardsAngle(current as float, target as float, maxDelta as float) as float
Description

Same as MoveTowards but makes sure the values interpolate correctly when they wrap around 360 degrees.

Variables current and target are assumed to be in degrees. For optimization reasons, negative values of maxDelta are not supported and may cause oscillation. To push current away from a target angle, add 180 to that angle instead.
	var target = 270.0;
	var speed = 45.0;

function Update () { var angle : float = Mathf.MoveTowardsAngle (transform.eulerAngles.y, target, speed * Time.deltaTime); transform.eulerAngles = Vector3(0, angle, 0); }
using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public float target = 270.0F;
    public float speed = 45.0F;
    void Update() {
        float angle = Mathf.MoveTowardsAngle(transform.eulerAngles.y, target, speed * Time.deltaTime);
        transform.eulerAngles = new Vector3(0, angle, 0);
    }
}
import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public target as float = 270.0F

	public speed as float = 45.0F

	def Update() as void:
		angle as float = Mathf.MoveTowardsAngle(transform.eulerAngles.y, target, (speed * Time.deltaTime))
		transform.eulerAngles = Vector3(0, angle, 0)