If you are looking to light a smaller fish tank aquarium and simulate dawn til dusk and moonlight phases then the TMC system might be just what you are looking for.
With their 2 way controller you can power and control 2 channels which could be a single TMC Aquaray tile or 2 TMC Aquaray strips (Grobeam or Aquabeam). This controller allows you to input the real time and then set the time at which you want the lights to start ramping up in intensity and then what time you want them to ramp down as well as what level you want them to ramp up and down to.
This is a fairly basic timer and as it fetches approx. £80 price tag it seems fairly steep for what it is. The 8 channel controller from TMC represents better value for money allowing you to control 4 times as many channels as well as having a storm function. Whilst this storm function might appear to be a bit gimmicky, it is still a good additional feature which I am sure would give more value to this 2 channel controller.
If you are looking to complete the TMC touch to your nano or small tank then go for this controller to give the fish less of a shock and more of a controlled environment however there may be more cost effective solutions available for smaller tanks.