On Sunday, May 20th, the Moon will pass in front of the sun, transforming sunbeams across the Pacific side of Earth into fat crescents and thin rings of light.
In the United States, the eclipse begins around 5:30 pm PDT. For the next two hours, a moon-shaped portion of the sun will go into hiding. Greatest coverage occurs around 6:30 pm PDT.
Link to the NES Virtual Campus home page.