Hi there,
I have a formula to calculate the beginning date of a field based on the week number from the year. The date in question may be any day, but I am only concerned with what the Monday for that week was. This is for a weekly reporting schedule into Excel.

For example, an event occurs on Thursday, I want to calculate that week number, and then produce what the date was for Monday.

The code I have used is:

datevar yearstart := date(year({StartDate}),1,1);   // Set the start date to the first of the year
numbervar weeknumber := DATEPART("ww",{StartDate});

//NOTE: The -2 is a fudge due to a bug in Crystal which takes the beginning of week 1 as the day that Jan 1 appeared on
dateadd("ww",weeknumber,yearstart)-2

You will notice that I have taken 2 off the calculation. This is because 01/01/2014 occurred on a Wednesday and so the formula is basing the start of every week on on Wednesday.

This fudge is fine for now, but as the end of the year comes up, I would like a rolling 8 week reporting cycle which may not work properly. Is there another way around this?

or this may work for you...?

That's the one - this is producing the week start on Monday which is perfect.