I am looking for a way to ensure StartDate parameter is always lower than optional EndDate parameter. I know CompareAttribute does something similar where it verifies that two parameters are equal, but I cannot find anything for greater/lower than another parameter. Is there something I missed or maybe a library with some extra validation annotations I could use? If not then I will need to make a custom attribute for this check. I specifically want an attribute check as it integrates with the rest of my application nicely.
Note: StartDate is a DateOnly EndDate is a DateOnly?