Views: greater than a date expose filter How can I only show the nodes that are greater or equal to the selected date from expose filter on views?

I'd like to have a dropdown/expose filter which allows me to select the nodes that their post dates are greater or equal to (past week, past month, past six month)
In Views, add a filter of Node: Post date.  You should see something like the image below (without example values changed):



Click Expose to have the filter exposed to your users, choose the operator Is greater than or equal to and choose how you want to filter the results (by inserting a date to be greater than or equal to or entering a value of "-6 months", etc).  This won't present a dropdown, but it will certainly add the filter you need for your view.