What is the difference between surrendering at that time and surrendering after a while in criminal cases?

The judge will consider the time of surrender when deciding to surrender. A judge has certain discretion and can give a light sentence. When a judge exercises his discretion, he will consider its social harm and personal danger. If he turns himself in early, it shows that he repents in time and has little social harm and personal danger, so he will consider it in a lighter scope.