Personal Financial Program

I've been recording my expense and income all the while using Microsoft Excel since I started my working life. I find it quite tough to maintain the Excel file. Thus, I thought of developing a simple application to record all my monetary transactions into database. Then, I can just generate reports from it when I want to analyse my financial status. I guess, my life would be easier with that. How long do I need to develop that? I'm not very sure, but I'll give myself a month for it. Will share my experience here if I encounter any problem during my development process..