Many people feel like they do their best work -- and are most focused -- early in the morning.
Research also finds that we're happiest in the mornings. An analysis of millions of Twitter feeds from around the globe, published in Science this fall, found that the use of words like "awesome" and "super" peaked from 6 a.m. to 9 a.m. After that, Tweets turn grumpier, finally hitting bottom from 3 p.m. to 4 p.m. Indeed, that's when words like "annoy" become downright prevalent.
In other words, not only are you likely to be groggy and less disciplined around 4 p.m., you're also probably not too happy, either. Doesn't sound like the best time to decide anything terribly important.
The best bet for making good decisions? Don't go on Twitter from 6 a.m. to 9 a.m.! Use that time to focus on work instead, especially if you're trying to think about long-term goals. The late afternoon is better spent getting a snack or going for a walk -- things you might Tweet happily about afterwards.