Hi.  I need to run a select on Mondays to pull data for 7 days prior to the Thursday of last week; i.e. Friday - Thursday inclusive.  I'm sure this is simple, but I work with dates so infrequently that I need a refressher.  Thanks for your help.

declare @dt datetime ='2015-09-07'

Select   dateadd(day,-11,@dt), dateadd(day,-3,@dt)

--where yourdtColumn>  dateadd(day,-11,@dt) and yourdtColumn <= dateadd(day,-3,@dt)

Try:

declare @LastWeekThursday datetime;
declare @CurrentDate date = CURRENT_TIMESTAMP;
set @LastWeekThursday = DATEADD(DAY, -7 + DATEDIFF(DAY, '19000101', @CurrentDate) / 7 * 7, '19000104')

select CURRENT_TIMESTAMP as Today,  dateadd(day,-6, @LastWeekThursday) as StartOnFriday,
@LastWeekThursday as endOnThursday

You could either use a calendar table or use some date arithmetic.

Example (date arithmetic using a reference that happens to be a Thursday):

DECLARE @dt date = CURRENT_TIMESTAMP;

SELECT
    @dt AS [@dt],
    DATEADD(DAY, (DATEDIFF(DAY, '19000104', @dt) / 7) * 7, '19000104') AS prv_Thursday_inclusive,
    DATEADD(DAY, ((DATEDIFF(DAY, '19000104', @dt) / 7) * 7) - 6, '19000104') AS prv_Thursday_inclusive_minus_6;
GO

- Calculate the number of whole 7 days between the reference date and today (... / 7)

- Multiply previous value by 7 (prv Thursday) and substract 6 days (Friday previous to previous Thursday)

Here is the same in one step:

SELECT DATEADD(DAY, ((DATEDIFF(DAY, '19000104', CURRENT_TIMESTAMP) / 7) * 7) - 6, '19000104') AS col1;

Example (using a Calendar table):

SELECT TOP (1)
    *
FROM (
    SELECT TOP (2)
	[date]
    FROM
	dbo.Calendar
    WHERE
        [date] <= CAST(CURRENT_TIMESTAMP AS date)
        AND DayOfWeekName = 'Friday'
    ORDER BY
        [date] DESC
    ) AS T
ORDER BY
    [date];

The non-RDBMS mindset is to do a lot of temporal math. A set-oriented way is to use a calendar table with an ISO week-date ("yyyyWww-d") column; you can copy it off the internet. This will be a general tool for other apps.

Thank you.  I'll study up on using a calendar table.

Naomi, if this is the interval end date, should it not be "2015-09-03 59:59:00.000" to make it inclusive of all records on that day, instead "2015-09-03 00:00:00.000"?

Thanks.

If would use Friday beginning of the day instead and use >= and < as comparison operators. Using End of Day is a bad practice (although I should admit this is what we're using at my current work place).