The daily bonus of Robux arrives once every 24 hours. If you are in Builders Club, you will get your daily R$ whether you log in or not. You can check and see that you got your money today by going to the Summary tab of your Trade section. The Past Day is what you got today. Past Week is the past week, and Past Month is all the Robux you have earned over the past 30 days.
For more information on gameplay and currency related matters, please check out the following links: