Some financial websites let you see earnings dates, but Slope makes this more useful to you but letting you see the dates specific to the items you follow. The custom earnings page is available exclusively to Diamond level members, and you can get immediate access by upgrading here.
The controls on the page are simple: two dropdown menus. The Watchlist dropdown lets you choose from any of your customized watchlists, and the symbols within that list will be displayed along with each company name, sector, date of earnings, how many days in the future the earnings will be reporting, and whether or not the report is before hours or after hours. The Time dropdown lets you further constrict the display to show earnings reported before the opening bell, after the close, or (rarely) during market hours.