Need help to create calculated members in ssas cube.. any example or hint??

I'm working on SSAS cube and would like to build following Calculated members or create on MDX query is fine to produce this data in report.

It wuld okay, if you can give example based on AdventureWorks database, internet sales amt for products etc.

1. Total Transactions count Weekend Sunday (i’ve date dimesion which holds day_in_week=’Sun’ for respetive dates)

2. YTD Transactions = Transaction count year to date

3. YTD Days = Count of days within calendar year to date

4. Zero months in last 12 = Number of zero transacting months in the last 12 months rolling window

5. Consecutive zero months = Number of consecutive zero transacting months in last 12 months rolling window

Need any MDX experts advise..

Thanks,

Niel