Look up in a range of dates if fall between two dates and result in a value from range

I have two worksheets.

Worksheet 1: lists all the news events that happened (News). In the A column is the mm/dd/yyyy hh:mm

Worksheet 2: has the list which contains an Open date and a Close date on each line. The format is the same, which is mm/dd/yyyy hh:mm. The formulas will be in this worksheet.

I need to write two formulas to accomplish 2 things:

o find if there is a news event exists no more than x minutes before the opening date and time in the list.
o find if there is a news event between the opening and closing date and time. If yes, then result the letter in column G of the News worksheet of the item that is closest to the opening date/time in worksheet 2.

I appreciate any guidance/advice on how to do this? Thanks.

-Stearno