Recording Data of my learning progress
I think the first point to address is how employers will know you are being honest about your logging. Maybe a better use of your time is to not put in number of hours, but projects and code references you've made so that the output is more concrete rather than just a number of hours.  The problem is I know plenty of people who put in 1 hour and learn what a normal person would learn in 5 hours. Think about the WOW factor in this.. what would be convincing to employers?  

Also, if its only you that are logging in hours and nobody else is going to see or use that program, you might as well use excel while focusing on whatever project you're passionate about.