Enchantments last X% longer

If I wield a staff that makes enchants last 20% longer, does it:

1) Apply to enchantments I cast on other people?

2) Apply to enchantments other people cast on me?

I imagine only one of the above is true.

I believe any enchantments YOU cast, weather it is on yourself or someone else, last 20% longer.

yep... any enchantment u cast... whether on urself or on another target... will receive the benefit of the 20% bonus

If your a monk you just hit the jackpot. It lengthens enchantments by 20% that you cast on yourself or other people. Use that enchantment monk skill (forgot its name) that increases enchantments up to 35% or so and you will be an enchanting machine.

Of course lengthening enchantments doesn't apply to mending or anything just so you know.