Reduces condition x mods on shield when is it applied?

Been wondering and searching for this one, but still didn't find any answer (tried guru, the wiki's, ...)

Been talking to guildies about it too, we all agree its a good question really, not one really come up often, and we all stay in the dark so far a possible answer about the following mods:

A Reduce condition X duration by 20% inscription, when do you get the benefit from it on a shield for example?

What I mean is will you get the reduced duration only when you have the shield equiped at the time of when the condition is applied?
Or if you have the condition currently and switch to the reducing offhand, will the remaining duration be reduced by 20%?

My gut feeling, and my guildies too, would incline towards the first (you have to have the shield pre-equiped, just like with the longer enchantment dynamic).
But this is just speculation, offcourse.

If nobody could help us here atm, I'll see to make a study of it, to find out how this dynamic works for reduced duration. But maybe somebody out there know the answer already or tested it yet?

cheers,

It's when the condition is applied. Switching to a blind reduction shield won't shorten an existing duration.