Recommended timelines for systematic UPSC exam preparation suggest starting at least 10 to 12 months before the exam date. This period allows candidates to cover the vast syllabus thoroughly, including foundational subjects, current affairs, and optional papers. A structured daily routine, with allocated hours for each subject and consistent revision, is crucial. Candidates should also schedule time for mock tests and interviews in later stages of preparation. Adhering to a timeline with periodic assessments helps maintain pace and identify areas needing additional focus, ensuring a well-rounded and comprehensive approach to preparation.