How much (in game) time does it take to build a kindom ?

i want to ad an "against the clock" element to my campaing, they will need to create/unite a kindom before terrible doom happens (and will have a prophesy as ticking clock), but i wonder how much in game time does it usally take for a group to pass from clearing their first hex to being able to have a proper kindom.

probably depends on how big of a domain you consider a "proper" kingdom.  In other threads, Alex has said that his ACKs campaigns usually involve some kind of external supernatural threat and that his campaigns tend to last around 5 in-game years, so that's probably a good ballpark.

Well, construction time aside, the main concern is probably money and XP, which will vary wildly based on how generous you are to your PCs and whether you start them at level 1.
 

This can be wildly variable, but... since you asked:

1. Each session of ACKS tends to take about one in-game month.

2. It might take about four sessions to gain a level from one to eight, and about six sessions thereafter.

3. Most characters become domain rulers at around level 9.

4. A kingdom is generally ruled by a 13th level character.

Therefore, you would be looking at [9 to 10, 10 to 11, 11 to 12, 12 to 13] 4 level advancements, times 6 sessions per level = 24 sessions, times 1 month per session = 24 months to carve out a kingdom from the time the party acquires its initial domains. 

To get to level 9 it will likely take them (8 x 4) 32 months, give or take, or about 3 years.

So if your campaign is starting at 1st level, you'd want to set doomsday five years ahead of the campaign's start date, or trigger your doomsday clock to start ticking down from 24 months from when they reach 9th level.

 

Thansk! thats really usefull data

Fascinating! My group tended to do sessions lasting about a week, with two sessions taking place on the same week if they're on a particularly intense dungeoncrawl, but occasionally do a four-five week timeskip to let characters recover, let the wizard learn his spells, etc.