TSQL Date Hints

-- From - http://www.itprotoday.com/software-development/cheat-sheet-calculating-important-dates.

--First Day of Last Year
SELECT DATEADD(YEAR, DATEDIFF(YEAR, '19000101', GETDATE()) - 1 , '19000101') AS [First Day of Last Year];
GO

--First Day of This Year
SELECT DATEADD(YEAR, DATEDIFF(YEAR, '19000101', GETDATE()), '19000101') AS [First Day of This Year];
GO

--First Day of Next Year
SELECT DATEADD(YEAR, DATEDIFF(YEAR, '19000101', GETDATE()) + 1 , '19000101') AS [First Day of Next Year];
GO

--Last Day of Last Year
SELECT DATEADD(d, -1, DATEADD(YEAR, DATEDIFF(YEAR, '19000101', GETDATE()), '19000101')) AS [Last Day of This Year];
GO

--Last Day of This Year
SELECT DATEADD(d, -1, DATEADD(YEAR, DATEDIFF(YEAR, '19000101', GETDATE()) + 1 , '19000101')) AS [Last Day of This Year];
GO

--Last Day of Next Year
SELECT DATEADD(d, -1, DATEADD(YEAR, DATEDIFF(YEAR, '19000101', GETDATE()) + 2 , '19000101')) AS [Last Day of Next Year];
GO

-- To Get First Day of Previous Month
SELECT DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) - 1, '19000101') AS [First Day Previous Month];
GO 

-- To Get First Day of Current Month
SELECT DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()), '19000101') AS [First Day Current Month];
GO

-- To Get First Day of Next Month
SELECT DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) + 1, '19000101') AS [First Day Next Month];
GO

-- To Get Last Day of Previous Month
SELECT DATEADD(D, -1, DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()), '19000101'))as [Last Day Previous Month];
GO 

-- To Get Last Day of This Month
SELECT DATEADD(D, -1, DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) + 1, '19000101'))as [Last Day This Month];
GO

-- To Get Last Day of Next Month
SELECT DATEADD(D, -1, DATEADD(MONTH, DATEDIFF(MONTH, '19000101', GETDATE()) + 2, '19000101'))as [Last Day Next Month];
GO

-- To Get Midnight Yesterday
SELECT DATEADD(d, -1, DATEDIFF(d, 0, GETDATE())) AS [Midnight Yesterday];

-- To Get Midnight Today
SELECT DATEADD(d, -0, DATEDIFF(d, 0, GETDATE())) AS [Midnight Today];

-- To Get Midnight Tomorrow
SELECT DATEADD(d, 1, DATEDIFF(d, 0, GETDATE())) AS [Midnight Tomorrow];

--To Get 11:59:59 Yesterday
SELECT DATEADD(ss, (60*60*24)-1, DATEADD(d, -1, DATEDIFF(d, 0, GETDATE()))) AS [11:59:59 Yesterday];

--To Get Noon Yesterday
SELECT DATEADD(hh, 12, DATEADD(d, -1, DATEDIFF(d, 0, GETDATE()))) AS [Noon Yesterday];

--To Get 11:59:59:997 Yesterday
SELECT DATEADD(ms, (1000*60*60*24)-2, DATEADD(d, -1, DATEDIFF(d, 0, GETDATE()))) AS [11:59:59.997 Yesterday];

--Julian Continous Day
declare @date datetime = N'05/31/2018'-- GETDATE();
SELECT DATEDIFF(DD, DATEADD(YEAR, DATEDIFF(YEAR, '19000101', @date), '19000101'), @date) + 1