Microsoft is hauling down Xbox Live for maintenance for 14 hours next Tuesday, 27th March.
Don't get too excited though - the good Major informs us that it's absolutely not a dashboard update, but rather just some "back end" work that was scheduled months ago.
The next big dashboard update is set to happen later this spring.
So when exactly is Xbox Live down for you? Well, if you're in the UK then it's 8am to 10pm. Elsewhere it's midnight to 2pm PT, and by clicking those links you can even find out when Xbox Live is down in Caracas. If they have Xbox Live in Caracas.