Question from Tess - Customary time for wearing mourning clothing

Hello! I am in the process of writing a novel set in the Tudor period (Henrician). Does anyone know for sure how long widows were supposed to keep black clothing (for mourning)? I read somewhere that there was no clear law about it, but what was considered 'proper'? The 1-year-period seemed to have only been set up in the Victorian era... or was it also applicable for the early sixteenth century? Many thanks xx