Moving down cells until date changes then calculate average

I have done a little preliminary searching for a solution to this but I couldn't quite articulate it in a short enough manner to find what I was looking for.

I have data sorted by date (Col A), gas test (Col B), oil test (Col C). The problem is there are a couple of dates that have multiple test results anywhere from 2-4 results per day.

So I need a formula in Col D that will check the date and if it is the same date as the one above it checks the next cell below it and so forth until it finds a date that is the next day and then will create an average of the gas test results of all the cells that it found as the same date. (And then replicate this formula again of course for the oil test results in Col E).

I was using an IF formula but could be overlooking something as the formulas are not my strong suit.

Thanks.

Couldn't seem to get the =AVERAGEIF formula to work with the ranges. I attached a sample of my data. So I'm trying to get the formula I can copy down in columns D and E to look at the dates so 1/1/2013 until it changes to 1/2/2013 and then take an average of the data from 1/1/2013.

Any help would be appreciated. Thanks.

forum sample.xlsx

Still trying to get the formula to work to take averages of the days as the next day changes. Don't know how to format the criteria where a new day is added to the date (i.e. 1/1/2013 --> 1/2/2013). Any help?