It's April Fool's Day on Wall Street so stay on your toes. Here's what to watch April 1st. We kick off a new month and a new quarter with a data deluge. First up, we'll get the ADP Employment Report for March ahead of the Labor Department's official report on Friday. And we'll get a better sense of how winter weather affected the economy with the ISM manufacturing Index for March and construction spending in February both out midmorning. On the earnings calendar, lighting company Acuity Brands and agriculture-focused Monsanto will report before opening bell. Software companies Rovi Corp and Progress Software will report after the bell.