I need to build a webform where one of the questions asks the user to pick a date from a list of 5 dates. Each of the 5 dates only allows 10 attendees. How can I track the number of people that have registered for each date and limit the number of attendees? Thanks for any help.
Go for some custom solution. I.e. create some content type with 5 integer fields where you will keep count of attendees per day.
Then hook that webform (hook_form_alter()) and add another submission handler function, like described here:
In that function (submit handler) read the form values increase counter if it has free space or shoot some message that no more places remained.