Ideally, running an ad for seven consecutive days on Facebook before making any big adjustments to the campaign. Your budget, goals, and audience are three factors to consider when deciding how long you want your ad to run.
If you have a limited budget, you'll want to make sure you're running your ad for a shorter period so you don't overspend. On the other hand, if you're looking to reach a larger audience or achieve a specific goal, you might want to consider running your ad longer.
Ultimately, the decision of how long to run your Facebook ad is up to you. However, it's important to consider the different factors that can affect your decision. Considering these, you can ensure you're running your ad at the right time to achieve your desired results.