The green flags simply try to notify you if Excel see's a problem. Excel has noticed that your formulas are not consistent in how they are entered.

I've had a look at the file and from row 6 onwards you have a space in between the cell reference (A5) and the + symbol. Best not to use any spaces in the formulas. So it should read =A5+7 which no spaces in between each part of the formula. So click in cell A4, position your mouse over the bottom right corner of the cell till you see the AutoFill icon which looks like a cross then autofill down the column again to overwrite the entries, repeat for column B, C, D, E, F and G and the green flags should disappear.

Yes if you change the date in cell D2 to 01/01/14 the dates will all update.
I'm about to go offline so will check in tomorrow to see if all was ok.