The problem is using other people's times from other days on other bikes with all sorts of other variables as a yardstick. Sure, you can compare your own laptimes during the day or through the year, but even that is touchy. A rider could be gradually improving throughout the year but because of the warming and then cooling weather, it will seem at first as if he isn't making any progress and then at the end of the year all of a sudden it will seem like he made a big jump forward.
Or comparing times through the day, if you want to be precise about it, means setting a baseline lap time from the start and then if any changes are made through the day, you should revert to that baseline setup (or technique, if that's what you're working on) to re-establish how performance has changed simply due to the environment. A competent test is one where you do an A-B-A test, A being the baseline setup and B being the modified configuration. An effective testing day will run A-B-C-D-A-E-F-G-A-H-I-J-A because the environment changes that much in one day.
All that to say, don't worry about your lap times unless you're testing or qualifying. Maybe it's important during an endurance race too, for strategy? I dunno about that.
