Anywhere between six-months, and six years that's a good answer don't you think?
How long a betrothal (engagement) lasts depends on the couple. Some engagements have been known to last for years! Others, especially in time of war, last a few days!
Not for so long.
11.5 years
It's up to the couple.
For all of our lives.
since 2006
Eternity
1minute
until death; ten years
Common law marriage in Texas lasts indefinitely as long as the couple meets the state's requirements for establishing a common law marriage, such as living together and presenting themselves as married.
Antarctica should last as long as the earth lasts.
Should last about 30 minutez