I am looking for an application where subcontractors can mark themselves as available or unavailable for work.
Background: We currently have varying work requirements whereby some days we will need 1 subcontractor and other days we might need 8. Currently, we are sending an email to each of them asking them to confirm their availability. This information is collated into an excel sheet where we can view availability. This works OK until people change their availability and the excel sheet is not updated.
Goal I am looking for a Web Service either hosted or self-hosted whereby individuals can log in and set/update their own availability in real time which can be viewed remotely.
Requirements We have looked at Doodle and others, however, these don't seem to be a good fit as they surround single pre-determined events, rather than just rolling availability, on an if-needed basis. A web-based is a requirement rather than SmartPhone app. API access to availability would be advantageous. Ideally free / Open Source, but willing to spend money on the right solution.