Feature and format of extrema

[MrMcFlyy]

I made this card for my solar energy production, which works great:

But i want to have only the time of the max-extrema. Of course i don't need the min-extrema, because the forecast will be 0 at night. And i want it in HH:MM-format. Is that possible?

At the moment i have:

show:
  extremas: max+time