It won’t be long, Timeline holdouts. Some time in the next couple of months, you’re going to log into Facebook and find a little message at the top of your screen. That message will inform you that you have seven days to get everything in order, because in that time your brand new Timeline will go live to all users.

Facebook has begun the final push, and users are being forced to switch their profiles from the old style to Timeline.

Facebook’s not doing it all at once, however. They’re not setting a big deadline day for everyone to make the switch. Instead, they’re slowly rolling it out to everyone. Very slowly, in fact. The first mention of making Timeline mandatory came all the way back in January, when Facebook informed all users that they had about two weeks left to enjoy the old profile before they dropped the hammer on holdouts. For a few months prior to that, Timeline has been available but completely voluntary. Users had to make the switch on their own, and once they did there was no turning back.

But the months passed, and Facebook continued to allow a good portion of users to remain Timeline-free. Facebook recently confirmed to me that everyone has their own “clock” for the mandatory Timeline switch.

“We’ve been rolling out Timeline since January. As it rolls out, each user has a seven day review period before their own timeline is visible to their friends, so the clock will be different for everyone depending on when it rolls out to them and when they log in…”

They also reiterated that Facebook hoped to have everyone switch over to Timeline by fall of 2012.

So, in the past month or so, you may have noticed a friend complain here or there about receiving the Timeline switch message from Facebook. It’s been happening more and more, and the response is generally negative. That would make since, considering the people being forced over to Timeline are the ones that have held out for nearly a year.

With all of the bitching and moaning about the big Timeline switch, we thought it would be interesting to conduct a highly unscientific study to determine just how many users there are out there who have yet to sign up for Timeline.

What we did was simply compare people’s total number or friends to the number of friends who have signed up for Timeline. Facebook tells you the latter when you visit the About Timeline page while logged in. Our informal survey included just a few dozen samples, but it was enough to display a pretty solid trend.

On average, 82.89% of our subjects’ friends had already signed up for Timeline. That means that just over 17% of users are still rocking the old profile. So between now and fall, Facebook has to push the Timeline to somewhere around 161.5 million users (considering Facebook has around 950 million monthly active users).

Of course, that’s a lot of extrapolating from a survey with a very small sample size, but the percentages of Timeline-enabled friends per each subject didn’t really vary. 94% of the accounts we looked at had a percentage of friends with Timeline within 4% of the 82.89% average. Our lowest percentage was 76.5, and our highest was 86.3. It really looks like around 8 in 10 Facebook users have already signed up for Timeline.

Facebook wants every user to be on the same page in the next few months. Resentment among these final holdouts is high, but there are also plenty of people who have stopped worrying about any privacy issues and learned to love the Timeline. As with every new Facebook feature, users are split on it. When you have nearly one billion users, you could institute a “free gold with every status update” policy and someone would bitch about it.

But Timeline dissent is pretty futile at this point. It’s happening, and if you’re a holdout, the time is coming sooner than later.