The lower button (8 o'clock) increments the hour, the top button (10 o'clock) decrements the hour.
The center button is the "sync" button: press it short to resync, or long for a full reset (don't do this in Australia - you'll lose the date for good).
I don't have the instrutions in electronic format either, but the above is about all you need to know.
The digit to the left of the date display tells how many days have passed since last sync. It stops at '9'.
I don't know if the Mega 1 gives up trying to sync after some time; if not, battery life may be negatively affected.