Not being able to identify the setting of a novel early can cause a loss of interest in the story because readers have their attention called to a defect before they swallow enough line to stay hooked. Setting is an integral part of any novel and is essential to the beginning of any story. Where and when are the basics of setting. While this isn't wrong, the cold fact of the date and place may take away from the drama of the beginning. Unless readers must be oriented before they begin to read the opening sentence, it's often best to be more subtle and not establish the setting so abruptly.
Readers open each new book hopefully, eager to participate vicariously in someone else's life.
At the same time, readers expect to discover very soon where and when the heroine is. Readers want to know whether it's morning or night, January or July, inside or outside, sunny or raining. Obviously directors need to have this information before they can set any scene for the camera to record. If, when writing a novel, you think of the reader's eye as the camera, you'll see the necessity of establishing the setting of your scenes. Though this can't be done so obviously as in a script, a little time, thought and effort will enable a writer to make the setting a part of the scene and allow the setting to add mood to the plot or to echo plot elements.