For Geeks & Brainiacs #14- Earliest Date & Time -

A certain 24-hour clock (military time) shows the time and date in the HH:MM:SS DD/MM format, for example:

You'll notice something unique about the time and date above, all the digits from 0 to 9 are used exactly once. But that's not the earliest time in a year that can be shown that satisfies this condition. What is?