high noon

noun3

1. •
   Exactly noon; midday (when the sun is at its highest).

   • The same streets that are inviting and quiet at high noon may be intimidating at night.
2. •
   A time, set out in advance, at which an important decision is to be made or a nemesis is to be confronted.
3. •
   (figurative) The zenith or apex of one's life or of a certain activity or era.