Depending on how your air conditioner or heat pump performs and what the current indoor temperature as measure by the device is, various temperature setting is required to reach your target temperature. 

For example, if your room is currently 28C and your set target temperature is 24C, the AC will start at a lower temperature such as 16C to quickly cool the room. As the room approaches a cooler temperature, the AI will adjust to a higher temperature to make sure the room is not overcooling. This is also why, sometimes when the temperature is already within target, it may alter between a temperature higher or lower from your target, just to make sure the indoor temperature is fluctuating within a smaller margin from your target temperature.