Where does the day start

It depends where you are from and where you live since of different time zones.

For me I would say 5AM or 6AM, or sometimes in the evening like 1PM.

So it depends.

I'm not so sure if this helped, but I hope it did. Have a good rest of your day!

d.) greenhouse gases

ń, wǒ shuō yīngyǔ, dàn wǒ huì shuō qítā yǔyán, rú xībānyá yǔ fǎyǔ yìdàlì yǔ hé pǔtōnghuà, suǒyǐ bùyào pànduàn, dànshì