Despite sharing one of two total words, "day drinking" is actually nothing like "night drinking" (also referred to by some as “drinking”).
There are many unique considerations not encountered while Night Drinking. Let’s say you’re starting with brunch at 1pm, which means you’ll be pretending to enjoy your first gross mimosa (more like a mi-gross-a, amirite?!?! No, iamnotrite.) by 1:15pm. Now is the time to start thinking about the future. If you put yourself on the proper path to really getting to know a cheesesteak at 8pm or so, you’re looking good. But getting there the right way is critical.
The most important area of focus during your Day Drinking is not, in fact, the drinking; that part’s fairly easy. It’s the eating. Proper eating will be your buoy through the day and ensure you remain the kind of person others aren’t ashamed to be seen in public with, amidst all sorts of boring sober people who will spend their afternoons shopping for infinity scarves at Coldwater Creek. Far more importantly, it will provide the foundation for a (reasonably) hangover-less next morning, allowing you to go to the gym/office/local water park all bright-tailed and bushy-eyed. The second is especially true if you are Sam Waterston.
Once you decide you will be Day Drinking the following day, it’s very important to be at least reasonably intelligent the night before. Drinking to Cope With Hangover Drinking is a drastically different kind of Day Drinking altogether and a very dangerous one at that. In an attempt to eradicate said hangover, you will almost certainly drink too heavily out of the gate, threatening your stamina. Ultimately, you will only succeed in rolling your hangover over to the following day, while adding additional hangover to the initial hangover. The worst part is, at some point you will have to stop drinking to cover up the rolled-over hangover(s). Have foresight and consider your painful future.
With all this in mind, do not stay out Night Drinking until 3am. A reasonable number of beers after work or at dinner is totally fine; you can even throw in a shot or two if it’s early enough and George Thorogood is insisting you do so. Show enough restraint to avoid waking up underneath your futon with your chinos on, and you will be rewarded.
Brunch is basically a made-up meal specifically designed to encourage Day Drinking and coat it with a thick glaze of classy, because rich people and Sarah Jessica Parker do it. This Day Drinking Guide strongly recommends brunch. It’s the perfect setting to establish a strong base of both food and booze, and sometimes they’ll let you sit outside while doing it (more on the importance of that later).
Generally speaking, there are two kinds of brunch: 1) bottomless-booze brunches that will serve you 2 hours' worth of mimosas that are mostly just generic orange juice from concentrate, and/or bottom-shelf Bloody Marys that might also be from concentrate, and 2) regular brunches, which are nothing more than meals at a restaurant willing to serve eggs later than normal. These typically include one free drink in the aforementioned offensive mimosa/Bloody category, or possibly zero free drinks at all.