Is there a way to generate custom fields on reports? For example, I create a report every Monday for the previous week's activity. I would like a subititle to read something like "Week ending <Month> <Date>, <Year>" that gets automatically populated for the previous friday date. Presently, it appears I would need to physically modify the report each time.

[edit] just saw you referenced Report Builder, I was thinking Advanced...  No, it's not possible in just the Report Builder.

In Advanced Report Builder it's a calc data item that you would add (Insertable objects), with the expression calculation roughly being Current date minus 3 days (Monday, minus 3 days = Friday) however your date calculation will be wrong if you miss a monday (say you run it on tuesday).  Do you have a date prompt for the range criteria of the report?  Using a prompt for a date range of the report and then simply displaying that prompt as a parameter on the report would be easier - since then you could run it whenever but select the desired week.

I can't access our report builder right now but will post up once I can on Monday with more details.  Take a stab at it however so I can tell how far along you get.  

I was looking at this as well and came up with a solution in Advanced Report Builder that is a bit more automated than what is suggested above. I still need to run this next week to be sure, but it appears to pull the Friday of the previous week.

In the header of my report, I have a standard text field: 'Week Ending '

Next to that I inserted a Query Calculation Object, and named it 'theDate'.
In the Expression Definition, I entered:

_add_days(current_date,-1*(_day_of_week(current_date,6)))

This basically says to go to subtract x number of days from the current date. I have this set for Friday, but if I wanted Sunday, for example, I'd change the 6 to an 8.

Again, I need to check this next week, but it should be a right start, anyway.

UPDATE: Checked this week and it functions as intended. I finally get to automate the sending of these reports!