Why can Daypart run on Mac OS 10.4 (Tiger)?
Primarily because there are technologies only available in Mac OS 10.5 that enable Daypart work more efficiently. To have the same functionality on earlier systems would require a bit more headroom and additional support considerations. After weighing those advantages and disadvantages, and anticipating a Mac OS 10.6 (“Snow Leopard”) release in mid-2009, I decided to start development with Mac OS 10.5. Future retro-development for 10.4, however, is not completely ruled out.