I've had the opportunity to work for nearly 5 years in a college/university gym. As such, I've noticed startling patterns surrounding the usage of the facilities, and the types of people one is likely to find on any given weekday (weekends are special, and don't necessarily conform to any specific rules) at your local post-secondary institution's fitness centre. Finding the proper day and time to work out is key to a good experience; hopefully you can find somewhere to fit in here.
Mostly Talking Monday: The busiest day at the gym, partially due to guilt resulting from a weekend of less-than-healthy living. The debauchery of the weekend also makes it difficult to work out as efficiently as usual, as the booze still works its way out of your system. It's important to work out in a group, lest someone Bogart your machine during the extended period of downtime between sets. If you're lucky, you'll manage to claim an upright gym with which you can accomplish many different tasks all from the same machine, while providing ease of conversation.
Time Spent Working Out: 15% of workout
Time Spent Recovering Between Sets1: 34% of workout
Time Spent Talking Amongst Friends: 51% of workout
Tepid Tuesday: Less busy than Monday, but still pretty busy. The weekend has worn off, but it's still too busy to get a really good workout in. There's a lot of standing around waiting for machines to open up, and, if you haven't convinced your friends to come back for Round 2, there are constant interruptions in between your sets. If you really know your way around a gym, you'll be able to minimize your downtime by understanding what machine works what muscle group, and calling an audible if you're interrupted.
Time Spent Working Out: 33% of workout
Time Spent Waiting For Machines: 67% of workout
Weird Wednesday: Wednesdays are the strangest days to be at a gym. The number of people has finally reached a point where the flow of the facility lets you actually work out for most of your workout. However, because of this, the facility seems filled with strange sights - people that didn't want to battle the masses at the beginning of the week, but are now ready to head to the gym. These people appear to have stopped researching fitness around 1981, and are not only poorly dressed for the gym, but are also doing bafflingly absurd workouts. These people are also the least likely to accept your advice on proper technique, so it's really not worth the hassle.
Time Spent Working Out: 75% of workout
Time Spent Wondering What the Hell He's Wearing/Doing: 25% of workout
Testosterone Thursday: Those weak-willed individuals who can't handle a full week's workout have now disappeared, opening the door for you: Rear Admiral Hardcore. In your compression shirt-t-shirt-hoodie combination, you stalk the gym, looking for the next machine to dominate. The availability of machines allows you to achieve maximum muscle-blasting variety in your workout, targeting several different muscle groups, thus negating the need to come back tomorrow, allowing you to do terrible, terrible things to your body at Pub Night.
Time Spent Working Out: 66% of workout
Time Spent Stomping Around the Gym: 32% of workout
Time Spent Powering Down a Protein Drink: 2% of workout
Flexing Friday: The emptiest day of the week at the gym. This is the day where one will find the truest of the true - people that know how to work out, wear appropriate attire, don't need to show off, and just appreciate a good workout going into the weekend. Unless there are girls around. Then, these people share one strange trait - the need to mentally recap their week's work by surreptitiously flexing in between sets.2
Time Spent Working Out: 25% of workout
Time Spent Talking About How Great You've Felt This Week: 24% of workout
Time Spent Flexing: 51% of workout
1 - But still monopolizing the machine because you've come in a group
2 - The key, though, is to make it seem like it's all part of the workout