In Kate Elliot's Cold Magic, set in an alternate-history Earth, there are two kinds of marriage; the long-term sort we think of when we hear the term, and a temporary marriage called a "Flower marriage" which lasts for a year (Maybe a year and a day? My memory is faulty).
The concept seems familiar to me, I swear I've encountered other fiction with a similar idea, but what I'm really wondering about is whether this is based on an actual practice from some culture in history.
So is this something she (or maybe someone else) came up with, or is it based on something "real?"