The temporal structure of Wuthering Heights has long been regarded as opaque or even flawed. This is explained by the fact that the years 1778, 1801 and 1802 do not entirely cohere with the numerous relative time references in the novel if, as scholarship contends, the years 1801 and 1802 refer to Ellen Dean’s narration of the story. By means of mathematically precise calculations and a grammatical analysis of the text, this critical new approach argues that the time frame of Wuthering Heights is sound if the years 1801 and 1802 date the writing of Mr. Lockwood’s diary. The crucial differentiation between the recording of Mr. Lockwood’s diary and the narration of Ellen Dean’s story leads to a deeper understanding of the intentions of the two narrators and the behaviour of the protagonists.