Yes, it is fine to change his feeding day.
However, it's less normal for him to refuse a meal that young.
- Where did you get him from?
- Was he eating before he came to you?
- What were they feeding him?
- What have you tried feeding him?
- Can you describe his set-up? Everything from what you are keeping him in, to what's in there with him, to what temperature is helpful.
Lets get little Salazar eating like clockwork for ya!