Downloadable to excel, stocks and etfs, ex dividend, amount, dare and yield. And free, if possible. The ones that pop up with google? Meh.
FINVIZ is good. Type "dividend" in the search box and off you go. TOS/Schwab is good also but you need to open an account.
There are many scan filters for the scan selection. Ex dates should be there. As far as membership goes, there is a free version for your email and then there are pay accounts but they offer a free trial to see if they are a fit for you.
I second Finviz. FYI there is a div strategy I use that is pretty good. On Jan 2, take the DOW 30 and divide by dividend into lowest 1/3, middle 1/3 and highest 1/3. Buy the middle 1/3 stocks and hold for the year.