Need small app to decide who works on saturday store shifts

I need someone who can write a small app with ExtJs 4 (preferable) to define my store's shifts on Saturdays. (You can suggest a more easy or appropriate way to develop this) I only need a way to save my 13 employees info like name, email and phones and then the application will generate a list of minimum six employees to work at the store on Saturdays. (Employee info can be saved on a XML file to avoid using databases for such small amount of info). The condition I need the app to handle is that every employee has to have one or two free saturdays each month. (I should input the number of free saturdays I want each employee to have) So my idea of this small app is that I save the employee data once (I can then delete, add or edit) and then I go to select the month I need, input how many free Saturdays I want each employee to have that month (I will choose that according to the number of Saturdays that specific month will have, which it will show me once I select the month I'm generating the shifts for) and the app will return a nice looking printable chart showing the lists of working and free employees for all the Saturdays that month. Always giving to every employee only the number of free saturdays I defined, not more nor less. So, is there anyone capable of doing this on the smallest budget possible?? Use the project board for any clarification please or contact me if you need further details before bidding.