Though the old serif logo had a "scholarly" feel which correlates with the purpose of a search engine. That said, I think the new sans serif logo is much better because it is more modern/forward looking which better encompasses Google's wide breadth (maps, chrome, mail, docs, etc).
For any time of day. Remember, once you begin a workout routine it's hard to stop; your body will crave the exercise. It may start out slow, but after one week, two weeks, you will feel stronger, healthier, have more energy for the positive things you want to do.