This will show you how to convert a range of dates into year/quarters. I'm also adding in the first and last date/time for each quarter. You should be able to use this to go forth and adapt to your requirements.

declare @StartDate datetime

set @StartDate = DateAdd(month, -1, DateAdd(year, DATEDIFF(year, 0, GetDate()), 0))

-- See Jeff Moden's article

-- The "Numbers" or "Tally" Table: What it is and how it replaces a loop.

-- at http://www.sqlservercentral.com/articles/T-SQL/62867/.

-- NOTE! A permanent tally table will always be MUCH faster

-- than this inline one. See the above article to create your own!

;WITH

Tens (N) AS (SELECT 0 UNION ALL SELECT 0 UNION ALL SELECT 0 UNION ALL

SELECT 0 UNION ALL SELECT 0 UNION ALL SELECT 0 UNION ALL

SELECT 0 UNION ALL SELECT 0 UNION ALL SELECT 0 UNION ALL SELECT 0),

Tally (N) AS (SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 0)) FROM Tens t1 CROSS JOIN Tens t2),

Dates AS (SELECT MyDate = DateAdd(month, N, @StartDate) FROM Tally ),

Quarters AS (SELECT MyDate, MyYear = YEAR(MyDate), Qtr = DatePart(quarter, MyDate)

FROM Dates)

SELECT MyYear, Qtr,

QtrStartDate = MIN(MyDate),

QtrEndDate = MAX(DateAdd(ms, -3, DateAdd(month, 1, MyDate)))

FROM Quarters

GROUP BY MyYear, Qtr

ORDER BY MyYear, Qtr