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Oneill0003

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Dates calculation

Hi experts:
Im having trouble trying to calculate MonthBegin and MonthToDate.
For this task Im always looking at the previous week, if the previous week has two months in it then:

MB = The 1st of the current month
MTD = Last Sunday of the current week
else
MB = The 1st of last month.
MTD = Last Sunday of the previous week

Example:
If I run it on  2007-11-07 then
MB = 2007-11-01 and MTD = 2007-11-04

If I run it on 2007-08-01 then
MB = 2007-07-01 and MTD = 2007-07-29

I keep trying and trying but not going anywhere, will really appreciate any help or tips!

Thanks
Isaac
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David Todd
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Hi,

--Beginning of this month is
select dateadd( month, datediff( month, 0, getdate() ), 0 )
-- Results 2007-12-01 00:00:00.000

--Beginning of this week is
select dateadd( week, datediff( week, 0, getdate() ), 0 )
-- Results 2007-12-03 00:00:00.000 which is a monday, so need to dial it back a couple of days.

hth
  David
Hi,

Previous Saturday is
--Beginning of this week is
select dateadd( week, datediff( week, -2, getdate() ) - 1, -2 )

HTH
  David
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Oneill0003

ASKER

dtodd:
Thanks for the responce, i know what the syntax to get MB and WB is, what  i need is help in figuring out how to calculate those dates by looking at the previous week and checking to see if the previous week has 2 months in it.

Look at the example provided.

IF previous week has two months in it then
MB = The 1st of the current month
MTD = Last Sunday of the current week

else
MB = The 1st of last month.
MTD = Last Sunday of the previous week

end IF

If I run it on  2007-11-07 then
MB = 2007-11-01 and MTD = 2007-11-04

If I run it on 2007-08-01 then
MB = 2007-07-01 and MTD = 2007-07-29
Hi,

I see two ways to do this:

Use the previous saturday calculation above to see if it is the previous month,

2 use the day of month and day of week to caculate if there are enough days in this month.

set datefirst 6
select datepart( weekday, getdate() )

select datepart( day, getdate() ) - datepart( weekday, getdate() )

if datepart( day, getdate() ) - datepart( weekday, getdate() ) >= 7
      print 'This Month'
else
      print 'Last Month'
      
HTH
  David      
Try this:


DECLARE 
	@dta AS datetime
SELECT 
	@dta='2007-11-07'
 
 
SELECT 
	CASE 
		WHEN month(@dta-
					CASE datename(weekday,@dta)
						WHEN 'Monday' THEN 7
						WHEN 'Tuesday' THEN 8
						WHEN 'Wednesday' THEN 9
						WHEN 'Thursday' THEN 10
						WHEN 'Friday' THEN 11
						WHEN 'Saturday' THEN 12
						WHEN 'Sunday' THEN 13
					END)
			<>month(@dta-
					CASE datename(weekday,@dta)
						WHEN 'Monday' THEN 1
						WHEN 'Tuesday' THEN 2
						WHEN 'Wednesday' THEN 3
						WHEN 'Thursday' THEN 4
						WHEN 'Friday' THEN 5
						WHEN 'Saturday' THEN 5
						WHEN 'Sunday' THEN 7
					END)
			THEN cast(Year(@dta) AS varchar)+'-'+right('0'+cast(month(@dta) AS varchar),2)+'-01'
		ELSE 
		cast(year(@dta-
				CASE datename(weekday,@dta)
					WHEN 'Monday' THEN 7
					WHEN 'Tuesday' THEN 8
					WHEN 'Wednesday' THEN 9
					WHEN 'Thursday' THEN 10
					WHEN 'Friday' THEN 11
					WHEN 'Saturday' THEN 12
					WHEN 'Sunday' THEN 13
				END) AS varchar)+'-'+right('0'+cast(month(@dta-CASE datename(weekday,@dta)
					WHEN 'Monday' THEN 7
					WHEN 'Tuesday' THEN 8
					WHEN 'Wednesday' THEN 9
					WHEN 'Thursday' THEN 10
					WHEN 'Friday' THEN 11
					WHEN 'Saturday' THEN 12
					WHEN 'Sunday' THEN 13
				END) AS varchar),2)+'-01' 
		END AS MB,
		convert(varchar(10),@dta-
		CASE datename(weekday,@dta)
			WHEN 'Monday' THEN 1
			WHEN 'Tuesday' THEN 2
			WHEN 'Wednesday' THEN 3
			WHEN 'Thursday' THEN 4
			WHEN 'Friday' THEN 5
			WHEN 'Saturday' THEN 5
			WHEN 'Sunday' THEN 7
		END,121) AS MTD

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Zberteoc:
I have been trying your code and it seems to work just fine, can you give me some explanations of what you are doing, and will these code work for any future year?

I'm planning on making these into a function so i can just call it from my dts package.

Thanks a lot for the help.
Hey Zberteoc:
Your code work perfect do you think you can explain a little what the code is doing, i follow part of it but will like a better explanation.

Thanks a lot!
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Zberteoc
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Clear enough!

Thanks!