As it might help to understand the viz better, I will try to dissect the timeline Mark Jackson build. It is really just build around an X/Y axis (column/row).
You only need 3 dimensions ([City], [From Date] and [Latitude]).
I now take to take you through the build, step by step.
1. Use MONTH(From Date) for X. This must be continually to make the line fill out the whole period.
2. For Y, we use (Latitude). Making it aggregate as AVG may be a good idea if your periods are overlapping. In any case, it must be continually, to create a vertical distance between each line. The latitude is the actual one for the city.
It now should looks like this
3. We now add [City] to the color mark. You can also add it to the detail mark, but then you'll miss out on the colors! . Because it is discrete, it will force the lines to break up.
Format it like Mark did and you got the same timeline.
To create your own timeline, you need to fill out the 3 dimensions with your own data.
[City] = the name of the city you lived in. It can be virtually any string.
[From Date] = the data you started living in [City]. In above example, you would need to at least be specific about the month (i.e. 01.09.2002 for september 2002). You can do it with just years though, or with days if you want it very detailed.
[Latitude] = this can actually be anything but to create the correct vertical distance (latitude) between the cities, you need the actual latitude. Notice that Mark did not use a [Longitude] because he made his vizualisation account for that with his own graphic (see below).
I hope it clarified things