Open source time card app that can be interfaced with Asteri


I am in the process of developing a time card application that integrates with Asterisk and I would like to know if anyone has done this and if so can you recommend an open source time card application that might reduce the amount of work required to connect it to Asterisk. I do not want to reinvent the wheel and write a WEB based time card app, I would rather spend my time getting Asterisk to connect to it.