By default, all standups repeat every week on the selected report days. Optionally, you can change the report frequency to every other week, every 3 weeks, or every 4 weeks. This can be done by navigating to your standup settings and visiting the Schedule section. Once there, you'll see the Frequency option for the standup.
For example, let's assume it's Sunday and you have a standup that runs Monday, Tuesday, and Wednesday. If you don't change frequency (repeat every week), the next day (Monday), your standup will trigger. If frequency is changed to every 2 weeks, for example, then your standup will only run again on the second week, meaning the next week will be skipped and the standup will trigger again the following Monday after that (2 weeks since the last).
It is also worth noting that the frequency always starts after the first standup week on a new standup or after the current week is complete if updating a previously created standup.