Your comment about time makes me think that you might benefit by changing that variable into an actual SAS time, or possibly datetime if your values cross midnight or exceed 24 hours. Values lists understands some time interval elements such as 'second', 'hour' or 'minute' if the values are actually times. OR you could could specify a BY element that is number of seconds and format the displayed values.   It might help to show some data that will duplicate the problem for one of the group/ period combinations.   Instructions here: https://communities.sas.com/t5/SAS-Communities-Library/How-to-create-a-data-step-version-of-your-data-AKA-generate/ta-p/258712 will show how to turn an existing SAS data set into data step code that can be pasted into a forum code box using the {i} icon or attached as text to show exactly what you have and that we can test code against. ... View more