Verify Date Then Calculate Sum Last 7 Days

[marepomana]

Hey Guys,

I am wanting to setup a part in my spreadsheet that will display today's date then calculate certain data in relation to the date. For example:

Date: 16/04/16 (I need Excel to automatically fill this, will Today() work?)
The sum of all values for the last 7 days: 127 (I need Excel to calculate the values from the last 7 days from column B)
This day last week the values were:Saturday: 12 (I need Excel to calculate the data from this day last week which will be a Saturday)
In the previous month the sum of all values for this day are: Last 4 Saturday's: 152 (Excel to calculate the values from the past 4 Saturday's)

I'm sure that this will be a simple answer but I have never worked with Dates to this extent. Any help or direction would be much appreciated

 

[FDibbins]

For the sum last 7 days....

=SUMIFS(sum-range, date range, "<="&today(),date-range, ">="&today()-7)