There is no definitive answer to this question as it can depend on a variety of factors. It depends on the person being interviewed and their preferences.
For example, if you are a morning person and feel more energetic and refreshed in the mornings, then a morning interview may be easier for you.
Alternatively, if you find that you perform worse under pressure and tend to get nervous before interviews, an afternoon interview might be preferable as it will give you more time to calm your nerves beforehand. Afternoon interviews allow time to settle into you day and helps you be more relaxed. You can have a chance to warm up and get into the flow of things by that point in the day, before attending the meeting.
Ultimately, it is important to assess your own strengths and weaknesses in order to determine which type of interview would suit you best.