neo-identity:

Sonnegender can be any of the following:

• A gender related to the sun.
• A gender influenced by the sun / by the placement of the sun in the sky.
• May be stronger during the day and on sunny days.
• A gender influenced by a kintype to the sun.
• A gender related to the Greek or Roman God Apollo, or the Greek God Helios, or the Roman God Sol, or any other sun deity.
• A gender influenced by one’s devotion to any of the aforementioned gods. 
• A gender that can be otherwise explained or identified using the sun.

Subsets of sunnegender include:

• Sonneboy
• Sonnegirl
• Sonnenonbinary
• Sonneagender
• Sonneandrogyne
• Sonne[gender]
• etc.

The name comes from the German word for sun, “Sonne”

-ap