Maybe we could work on a collaboration effort.
I'm thinking about it and the issues are the scheduling may need to be industry specific. For example an auto repair garage just needs a list of people that are supposed to show up today while a lawn care company will need recurring visits which may be weekly, bi-weekly, X number of days between or once every 6 weeks depending on the service provided. Of course including a "one time job" option would be useful to the latter while being the main choice for the former.
Another concern is making it updateable via a web interface and deciding on where to keep the databases.