Reading List - Old to New sorting

I tend to add more to the reading list for later that I will actually read. I want the oldest added entries on top, so that I am confronted more often with sites that I didn’t check for the longest time. The current sorting (new to old) will make me forget about the oldest entries which just results in the list getting longer and longer. If I am confronted with the oldest first, I might decide that it is not relevant anymore by simply removing it, thus my list has chance to shrink again.