When it gets dark at a time that becomes a nuisance, and prevents people from doing things they would like to do, then i would call it too early. personally i much prefer to cycle home from work in the light, since i go through the countryside, and i would like to get home and look out of the window to at least see the garden for a while before darkness sets in. Come December it feels appropriate for the sun to set at 4pm. Its the decent of darkness in late October that takes a while to acclimatise to.