DALLAS, TX — Untold millions are poised for the Aug. 21 eclipse of the sun on Aug. 21 (sorry, Texas, it'll only be partial from our horizon), but the date — when many kids gear up for the first day of school — is inconvient for one mom. "Most kids go back to school that day," the mom wrote the Perot Museum in Dallas that's hosting a solar eclipse party. "Can it be done on the weekend?" The answer is no. The date of the solar eclipse cannot be postponed for another day.