How to fill a prompt in webi with current date?

Question

A webi report is being generated on BEx Query.
IN BEx query variables are defined for some date fields to prefill them with current date.
Foe ex. there is license start date. For this field variable is defined so that in variable screen License start date is automatically filled with greater than or equal to current date(which is system date). WHich is a mandatory variable.
On BO side, a webi report is being developed on a Universe (based on this BEx query).
When the webi report is run, the license start date(mandatory variable in BEx) is automatically prompted, but date is not getting prefiiled with current date.
How to prefill this prompt with current date?
the prompt should be like
LIcense start date >= <current date>

Answer 1

Hi,
Yes, it isn't possible to reference anything like 'Current Date' in the universe (like you would with a SQL data source).
The solution I have seen recently goes like this, I don't know the exact details (so I might have some terminology wrong), but someone with ABAP skills should get what I mean.
Assuming you want to filter on 0CALDAY.
In ABAP, create a customer EXIT that calculates the current date as a number (so today might be 40651). Do the same for 0CALDAY.
In the BEx create a formula variable that references each of those, then a Formula Key Figure (I forget the exact name of them) that's just the current day number minus the 0CALDAY number. This gives you the 'age' of that row of data.
Your Webi report can then have a built in filter (or prompt with a default value) of, say Age <= 30. The report can be scheduled and will always run with the last 30 day's data.
We actually did the customer exists to show the 'age' in months.
Sorry I can't explain it any better, but it's working great for us.
Hope that helps.