Aspirants should ideally revise their study materials every **two to three weeks**. Regular revision is crucial in retaining **key concepts** and enhancing retention, given the vast _UPSC syllabus_. This frequency allows candidates to assess their understanding and fill knowledge gaps early on. Additionally, spaced repetition aids in long-term memorization. Setting aside specific times for revision in the study schedule ensures consistency. It's also beneficial to revisit complex subjects or topics that are challenging. Overall, integrating regular revision into the preparation strategy optimizes learning and bolsters exam readiness.