Drupal 7 Date - Is there a way to change field settings if there is data in it already?
I got this working by doing the following without having to write any code. Keep in mind im only doing this for the DATE type fields:

example:

my old field: field_eventdate

my new field: field_placeholder


create the same field type with a different name and the options you want.
open up phpmyadmin
goto the table: field_config
search for the new field you created (field_placeholder)
click on the data column blob and download that.
search and edit field_eventdate and upload the file you downloaded which contains the new settings.
do the same exact thing for the table: field_config_instance
now we have to update the table structures of the field to encompass these changes. I first inspected the strucuture of the new field i created and see what the old table was missing. Once you have that down, create the missing columns in the old field that exists in the new field. 
Do #8 again but this time for the revisions table. In my case it would be: field_revision_eventdate
delete the field_placeholder via the content type page as you wont need it anymore.


let me know if this worked for anyone else too.