How Do You Get Older in Ocarina of Time

After you get the three Spiritual Stones (Kokiri's Emerald, Goron's Ruby, and Zora's Sapphire), go toward Princess Zelda at Hyrule Castle when suddenly Princess Zelda and Impa will go racing off. Princess Zelda will throw the Ocarina of Time into the moat around the Market and Ganondorf will appear. After the cutscene, dive into the moat and retrieve the Ocarina of Time. A scene will appear of Zelda teaching you the Song of Time. After you learn the song, go to the Temple of Time in the Northeast part of the Market, and play the Song of Time at the alter to open the Door of Time. Walk inside and grab the Master Sword from the pedestal and you will have gotten 7 years older.