You might get lucky, but I don't think that it's likely you'll be able to get an entire 9am to midnight timelapse capture with no human intervention at all, regardless of the equipment chosen, barring the construction of a light-sensitive intervalometer which can make adjustments shot-by-shot. The reason for this is that it is still a complex and 'fiddly' task for cameras to handle lighting changes during timelapses (especially during the critical day --> night transition which can easily span more than 12 stops of light).
Having said that... With the equipment you have, the only potential way to achieve a smooth day-to-night timelapse transition with no human intervention is to do the following:
- take bracketed exposures with as many stops between the brackets as your camera will allow, cross your fingers that at least one of the bracketed exposures will be 'in the ballpark' of properly exposed, and then use fading transitions in a video post-production solution to 'fake' a smooth transition when the most drastic day --> night lighting changes will occur.
- Set your camera to its Manual mode, focus the lens, set the aperture, and then disengage the lens from the camera by unlocking it and giving it a quarter turn so the communication contact points are no longer touching.
- Start the timelapse and hope for the best.
Yes, I have built one. No it is not easy, and it does require both electronics and imbedded circuit programming knowledge (or at least the time and willingness to experiment with them). Sadly, there is currently no commercial equivalent on the market, though I'm aware of a couple different manufacturers who have been poking around the Timescapes forum (where all of us hardcore Timelapse geeks hang out and experiment with these sorts of things). So at "some point" down the road there might be a commercial option available.
Which if you're planning to shoot at 5 second intervals will work out to be approximately 32,400 individual frames, so... Make sure you've got plenty of space on that tethered laptop! :-)
 You'll probably want to set your aperture to give yourself a relatively deep depth of field... Somewhere between f/8 and f/11, I'd guess...
 Your camera resets its aperture between every shot. While it is accurate enough for still shots when performing this reset, there is still some variation every time it performs the operation... Which will cause constant flickering throughout your timelapse unless you disengage the lens so the camera can't change the aperture between shots.