I was wondering if anyone on here was surprised like I was when I noticed a 12/87 date code on the front drivers side rubber brake hose! 25 years old! They still look good but I am already scheduling to get them replaced. How long should they last? 
The 10/87 dated hose does not surprise me, it just means that one has been replaced. As for how long these hoses last, it depends on a lot of things, climate the car resides in mainly. Generally they are good until the exterior rubber jacket that you see starts cracking badly, usually at the ends by the metal parts. Sometimes the inside hose goes bad, but usually the outer goes first from exposure to the elements.
Hope this helps.
Bob