My date dimension is Year-Month-Day.

I can use the LastPeriods function to retrieve the last X days of readings:

LastPeriods(7, 
StrToMember
(
"[Date].[Year Week Day].[Date].&[" + FORMAT(Now(),"yyyy-MM-ddT00:00:00") +"]"
)   
)

I now need to retrieve daily readings for the current quarter. I think I need to use the current date and quarter and calculate the range from the start of the quarter to the current date as my LastPeriods value. This will give me number of days from the start of the current quarter to current day.

I also need to return the last 3 months from the current day. So should I just roll back 12 weeks from today, i.e. 12*7 = 84 days = LastPeriods(84.... 

Hi D,

For all days in the current quarter, you could navigate to the first day of the quarter using .parent and .firstchild. For example, if your hierarchy was Year, Quarter, Month, Day, instead of LastPeriods, you could use

StrToMember
(
"[Date].[Year Week Day].[Date].&[" + FORMAT(Now(),"yyyy-MM-ddT00:00:00")
+"]"
).parent.parent.firstchild.firstchild

:StrToMember
(
"[Date].[Year Week Day].[Date].&[" + FORMAT(Now(),"yyyy-MM-ddT00:00:00")
+"]"
) 

Hope that helps,

Hi DarrenOD,

According to your description, you want to get set of members in last 3 months. Right?

In this scenario, since each month has different days, it's not accurate to use previous 84 days in LastPeriods() function. For your requirement, we can use ParallelPeriod() function and specify the level expression we need. So your expression can be like:

ParallelPeriod(
[Date].[Year Week Day].[Month],3,
StrToMember
(
"[Date].[Year Week Day].[Date].&[" + FORMAT(Now(),"yyyy-MM-ddT00:00:00")
+"]"
)
)
:
StrToMember
(
"[Date].[Year Week Day].[Date].&[" + FORMAT(Now(),"yyyy-MM-ddT00:00:00")
+"]"
)
 

Reference:
ParallelPeriod (MDX)

Regards,