As soon as I had two columns in the logbook I started adding them up to equal total time. It was pointed out to me that I didn't have to log daytime since TT minus night would equal day. But I still ended up adding all the categories and class to equal TT and Solo, PIC, SIC, Dual Received and CFI to equal TT when each page was filled. Finally went LogBook Pro at 15,000 hours. Lots and lots of data entry.