Ideas on how to schedule geographically?

Is this the 'native' map you're using? If so - the best option to keep this as a native solution is to maybe have two pages side by side - the map on one and a grid edit on the other and hover over the map to figure out which ones you want and then toggle over to the grid edit and enter the date. 

The native map is just going to be a view so it's not going to have the kind of functionality to help with scheduling like it sounds like you're looking for. 

You can go the custom code page route - where you could build your own custom map and there is functionality in the Google API as an example where you could draw a radius or area around a collection of points and filter only what's in that area and have a process to then schedule them. 

If you want to get wild with it - you could also try some kind of 'auto schedule' and create a script that does a simple calc of the distance between each point (haversine formula) and find all the ones that are close to each other and just auto-schedule them in a batch job that your team can then review and make any adjustments.