Monty, check out this page on the same webpage link given earlier...
http://timelapse.theusner.eu/step-by-step.html
forget the dslr stuff, you'll have to do it manually...but look at the chart re: exposure in general for night, dawn, sunset etc...
One thing about the light changing over time... you don't wanna really keep compensating all the time or else as it gets darker you will actually see it stay the same ( cause you're compensating for it getting darker ). You sorta WANT to let it get darker so show the light changing. But you don't want to lose your resolution etc either ( too much noise, too dark to even see differentiation between building and now darker 'sky' etc )... sooooo, although I only did this type thing with a still camera in the past.... my advice is you pick out a spot in your scene that is roughly gonna stay close to zone 5 in a grayscale... probably some part of building a little ways off from a streetlight or something ?... this is similar to using a gray card and spot meter to read it..but you have to guess where that gray card is in your scene...
Since you have to do this manually it would help if you really DO have a spot meter and 3deg or tight narrow area to read the exposure...
As it gets dark at first you can probably leave it get darker... is normal looking...and at some point you decide to open iris 1/4 stop or so to try and keep that " tone " you chose as your gray card close to the start of your series of shots.... then after another period of time ( dont know how fast sun sets where you are ).. open another 1/4 stop...and just keep doing that throughout.
I would start at a high ISO to begin with so you don't have to change it at night...say around 1000 iso or so...( your camera probably has good sensitivity at night noise wise )... So you start with a higher f stop and gradually open up to keep your gray tone area sorta close to where you want it...
Then the color ( gets more blue as night happens ) will also help you let it look " real " ... plus the color of lights in buildings and streetlights will add to that realistic look of it getting dark ( day to night ) etc...
I had to do that manually using the red camera during a test last year... and started at 1000 iso and it worked out okay at night with some streetlighs, car headlights and so on at the end of the series of takes.
good luck and if its for a client do a test first ...hehe... and bring stuff to drink, eat and something to sit on.