The Monday of the week following the following week. As an aside, I'm not even sure if the fact that this would work one way rather than another is a matter of which language is spoken (e.g. English), or whether the same reasoning as would be given by answers on this group would apply to other languages as well (as a matter of pure logic). More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.