Comet Elenin as seen by NASA's STEREO spacecraft on Aug. 6, 2011. CREDIT: NASA A NASA spacecraft aimed at the sun shifted its unblinking gaze to an approaching comet last week to snap a new photo of the icy object as it flew by. The image shows the comet Elenin as it passed within 4.3 million miles (7 million kilometers) of one of NASA's twin Stereo sun-watching spacecraft during a series of deep space photo sessions that began on Aug. 1. NASA rolled the Stereo-B satellite to give its instruments a view of the comet flyby, officials said. From Stereo's observations, the fuzzy comet Elenin can be seen streaking across a small portion of the sky. The comet was seen by Stereo's HI-2 telescope between Aug. 1 to 5, and by the higher resolution HI-1 telescope between Aug. 6 to 12, NASA officials said. Stereo mission scientists planned to take photos for one-hour every day through Aug. 12. [See the Stereo probe's new comet Elenin photo]

IRC +10216 or CW Leonis is a well-studied carbon star that is embedded in a thick dust envelope. It was first discovered in 1969 by a group of astronomers led by Eric Becklin, based upon infrared observations made with the 62 inches (1.6 m) Caltech Infrared Telescope at Mount Wilson Observatory. Its energy is emitted mostly at infrared wavelengths. At a wavelength of 5 μm, it was found to have the highest flux of any object outside the Solar System.[4]

People these days . Listen, no one will know the "exact date", it is an ongoing process, it is not something that just "happens" on a "specific date".