The earth's axis is tilted so in addition to needing to know the timezone and the date in a solar sense, you also need to know the latitude and need to be able to combine those three things in your head... in practice you just look it up instead.
Oh, that's easy: the sun never sets on the British empire.
Seriously, though, time zones do not help with that. The sun sets at nine in the evening in Leicester in July. Can't be helped, the length of the day is different.
Time zone info doesn't just pop into your head. You have to look that up too, or at least receive it somehow. Sunrise data could be obtained the same way. The difference being, of course, that you wouldn't need to look up anything that didn't care about the sun, while time zone info needs to be known to make sense of any time.
