Graphing only data from certain dates

I have a database that is filled in by multiple people at different times – I would like to create a graph that shows a time series analysis of only the last quarter’s data. I know how to set up a table such that as the table is updated or added to my plot also updates. My question though, is there a way to tell excel to only graph say, data from 3 particular months, in the order they occur, without going in and sorting my data each time?

So for example, my list is say 100 rows long – each row has a date and a data figure. The rows are constantly being added to, and not in time sequence. So right now I may have row 100 dated 6/1/14, and then row 101 is added by someone and its 1/1/14, and then row 102 i added and its 5/1/14, and so on. Is there a way to tell Excel that I want it to look at my table and graph sequencially only the last 3 months of data. So in the above example, row 102 would appear on my graph automatically, but row 101 would not since its more than 3 months ago. Is there a way to do this, or do I need to just sort my data by date each time and just create my graph from that?

Thanks for any help/

Use a pivot table: Guide to pivot tables

1. Make sure your data is in a table – If not select the data and on
   the home tab press Format as Table
2. While your table is active go to the table’s TABLE TOOLS that pops up
3. Hit Summarize as Pivot table
4. Choose where to place it
5. Build your pivot table as needed – Dates in the series, count in the values

In the pivot table’s PIVOTTABLE TOOLS tab go to the ANALYZE tab
Press PivotChart

Build your chart as needed.

Now you have two options:

1. Use the dropdown arrow above the dates in the pivot table to select the date range you want (you’ll need to tick Select Multiple Values)
2. In the pivot table’s PIVOTTABLE TOOLS tab go to the ANALYZE tab and select Insert Slicer, choose the date field and drop that wherever you want. This will create a presentable tool next to the graph that can be used to change the date range – hold Ctrl and click to select multiple dates.