QB Trending Reports

Can you explain a bit more about your data?  But typically you would use a chart where the X axis is the Date grouped by week or month and the Y axis would be what you are measuring. 

You can also use Summary reports if they prefer to see numbers.  Again, one of the groupings for the summary report would be a date field, and grouped by say week or month.  Often with Summary reports the date field is use as a column group and the regular row grouping are used to categorize what is being measured.