Overall, Saturday and Sunday are fairly equal choices nationwide. Referencing a study that contained 80,000 events, a few nuances started to reveal themselves. In the Bible Belt, Midwest, and South, in general, most events took place on a Saturday. In fact, the state of Mississippi did not have one single event on a Sunday. As you move West it became much more of a mixed bag as to which day came out on top. The trend on the East coast favored Sunday events.
The longer your event is, the more time you will have road closures and the more disruptive your event will be in general. Events that are 5k or shorter have a relatively short window of time that a relatively small number of roads or intersections may be disrupted. A race that is 10k or longer will require significantly more time to complete the event. There is a reason you see most major marathons in the US take place on a Sunday. Overall, for most locations a Sunday morning will mean less traffic in general. Go out on your potential course on both days during the time of the event and walk around and make observations and look for potential trouble spots.
Related: Choosing a Route For Your Running Event
This is related to course logistics, but warrants some additional discussion. A race that starts and finishes at a city park is very different than a race that finishes in a historic downtown area or near a busy retail center. You will be basically taking over this area for many hours until the completion of the event and all the infrastructure is broken-down and cleared away. You need to consider what other user communities or local businesses will be impacted by your choice for the start/finish. Be proactive and reach out to everyone. Some of these business and groups could potentially be your sponsors or volunteers if you work to include them in your event.
This is where you really start to look at which day your specific community will respond the most to your event. Some of this depends in what groups you're targeting. Soccer moms and busy families for a Fall event? At this point, kids are back in school and have lots of soccer, football, and other extracurricular activities on Saturday mornings. A Sunday might be best in this case. Are you in a college town or NFL city? Be aware of other large events that could siphon off a big chunk of your targeted demographic.
Existing Similar Events
This may seem too obvious to mention, but you would be surprised how many people start an event without regard to existing, similar events. As far as other races go, you do not want to schedule your 5k the same weekend that already has several other events of the same distance taking place within a relatively close geographic range. Take the time to do some research. Maybe you are targeting a completely different crowd. If there is a large event taking place in your community and there is not a race involved, maybe you could piggyback off all the buzz and excitement of that non-running event.
Related: Turn Your Event into a Runcation
So there you have it. We did not answer the question for you, but hopefully gave you some important things to consider when picking Saturday or Sunday for your event. Whatever you choose, we know you will make it great. Here at RaceDirector we want to help make that job easier. Be sure and browse the archive of our Race Director Blog for more useful tips and information.