1.) Date and time, in your time zone. Or in zulu time. But I'm an army brat so I'm used to having time like that. I'll convert them all to UTC later.

2.) For fill post data and I want a copy pasted time and date of when the first fill comment was posted. (Does this make sense? Your comment was posted on 2015-08-24 09:10 pm (UTC))

3.) Yes, do leave it blank.

Glad for your questions, hopes this clears it up.