Many babies have particular times in the day when they cry and cry and are difficult to comfort.
Early evening is the usual bad patch. This is hard on you since it's probably the time when you are most tired and least able to cope. Crying like this can be due to colic. Everybody agrees that colic exists, but there's disagreement about what causes it or even if there is always a cause. The crying can go on for some hours, and there may be little you can do except try to comfort your baby and wait for the crying to pass.