日不见阳光的暖也不见月光的蓝
[rì bù jiàn yáng guāng de nuăn yĕ bù jiàn yuè guāng de lán]
A Day Without Warm Sunlight or Cool Moonshine. It poetically describes feelings of loneliness or depression when both day and night feel void of comforting elements - warmth from sunlight or solace in the cool moonlight.