Sorry you can set a value at anytime (for the most part). The problem is you can’t set a field value on before load When using go to record you are loading the container record in the UI and while trying to load it also trying to set values. This can only be done on create If you use before submit or after submit then it will work anytime. But that means someone needs to edit and save the container record Alternatively you can use a scheduled workflow to set the values every 30 min