Cumulative Sum of Units Per Week

Hi,

I am trying to make a summary for a units distribution on a weekly basis.
I have the units distribution data on a daily basis which needs to be summarised per week.( The cut-off day is Monday)
First Monday in the data is 21-Nov-16 so all units upto and including 21 should be added up in the cumulative units.
Similarly near to date 28-Nov units for dates 22,23,....upto 28 should be added up.
I require a formula to get this result in Column C (I have attached workbook with data and desired output)

VBA Request
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I would like to get a VBA solution for the same.
After the cumulative units for all Mondays are obtained,the other rows should be deleted and only the Monday dates with cumulative values should remain.
Also the column for daily units should be deleted.


Thanks in advanc