How does the History/Achievement system work/update?

[Azurymber]

I've noticed some people have the new NMs listed as killed already. I've gone and killed all 20 and would really like to make sure i've actually killed them all. But mine still hasn't updated at all. Does it update at a certain time? or do you have to do something to get it to update? or how does the history/achievement system work?

Sometimes it has seemed to take days for mine to update.

thanks

[Holy_Dragoon]

I went and checked mine this morning after all the killing we did last night, and did not find a single one listed on it. Made me kind of sad as we formed a LS party and killed every single one. I missed maybe 1 or two due to being AFK. I planned to check using my history to verify which I had missed.

[Peregrine]

Geez did i really only kill 4?
They'll automatically update eventually.

[Azurymber]

over 20 hours now and still no update, yet other people had it within 5min of killing the nm. I'd just like to know how the system works.