Step 4
Link additional fact - He won Nobel Prize for this discovery. Answer: February 28, commemorating CV Raman's discovery of Raman Effect.
Advanced Shortcut: Group days by themes - Health Days (World Health Day April 7, World AIDS Day December 1), Environment Days (World Environment Day June 5, Earth Day April 22), Education Days (International Literacy Day September 8, Teacher's Day September 5). This thematic grouping prevents confusion.