While preparing a project plan, I had a strange problem. I wanted to highlight all the project tasks that fall with-in a certain date range. At the lowest level, the problem is like this:
There are 2 ranges of dates (a,b) and (x,y) and I want to know if they overlap (ie at least one date common between a,b and x,y)
The formula for testing such a thing seemed tricky at first. So I drew the conditions on paper to get clarity on what we should test. Evidently, there are 4 ways in dates (a,b) can overlap with dates (x,y) as shown below:
Now, we can test for the overlap condition using a formula like this:
If x is between a and b
or a is between x and y
then overlap
else do not overlap
As you know, there is no formula in excel like isbetween(). So we have to break it up to 2 conditions and an AND() Formula. Finally the formula becomes,
=if(or(and(x>=a,x<=b),and(a>=x,a<=y)),"Overlap","Do not overlap")
Now, it seemed like quite a big formula for testing if 2 ranges of dates overlap.
So, I continued my quest for even shorter formula.
After sometime, I realized that if we test for non-overlap instead of overlap, we can write a shorter formula.
Do not understand? Let me explain.
While there are 4 ways in which (a,b) can overlap with (x,y), there are only two ways in which (a,b) cannot overlap with (x,y). See this to understand:
Now, testing above conditions is very straight forward in excel.
the formula becomes, =if(or(y<a,b<x),"Do not overlap","Overlap")
The formula is much shorter and easy to maintain.
I was able to use it to test if a set of tasks in the project plan are running between given dates (for eg. next week). All is well in the end.
How do you test overlap conditions?
Do you ever have to test overlap conditions? What kind of formulas have you used? Please share your formula tips & tricks using comments.
23 Responses to “Learn Top 10 Excel Features”
What it looks like if excel without formula?? 🙂
It would be not excel it would just be fancy tables in which you could just use power point. (Chandoo) would Access be an alternative?
Awesome piece of work!!!
Great article.
Chandoo - my biggest interest in the article was the awesome word-graphic at the top - where did you go to get it done into a shape?
@Rich.. thank you. I used http://www.tagxedo.com/ to generate this word cloud. I took all the comments in the original post, pasted them in tagxedo website and set up the shape etc.
Awesome Chandoo.. You need always needs coffee to start up with. BTW , how did u created the Heart Shaped picture filled with High Repetitive text in it .. Please put it on your Next blog ...
Chandoo, good article. I’ve added a link to it from Connexion – our collection of the most useful and interesting spreadsheet-related articles from the web. See http://www.i-nth.com/resources/connexion
Hi,
Just one small question. Where the hell have been I in the past for not discovering this website sooner?
I've lost a job interview recently where even though I had the subject knowledge, I was not upto their mark in Excel.
Thank you for all the free tips, guidance and for creating this forum environment.
[PS: I've just been through the site for the 1st time, and have signed up for the newsletter. You can expect pretty stupid questions from me soon]
Hy Chandoo, you always inspire me with to explore something new in excel. This data structure table is only for excel 2007 or compatible to 2010. I recently installed latest excel version 2013 in my System and experience problems regarding operating according to previous one. I'm waiting your article relates to that excel version.
Thanks
Awesome article Mr. Chandoo and that is a awesome heart shaped pic you created. Great tips as well.
[...] Learn Top 10 Excel Features | Chandoo.org – Learn Microsoft Excel Online. [...]
Chandoo is awesome..
Thanks, i got better, And i always get 90.50 in my grade card but now i get 96.50 i improved because of the tutorials you gave, Thank You Very Much Chandoo Guy.
Hi chandoo, i am intersted in seeing the video or step by step done procedure of analysing the comments and presenting in the data percentage steps. I think this one would be first step in finding out how generally happens data calculation. Thank you.
As well i would like to know how to get that black shape art of your face which i see in chandoo. I am interested in making it for me.
Nice to see the features considered by Excel users to be most useful. It might be a good idea to also analyze StackOverflow Excel questions to see what keywords appear most often.
Here are my top 10 Excel Features (for advanced users):
http://www.analystcave.com/excel-10-top-excel-features/
Thanks a ton for this it totally helped with my homework ????
Very good effort
Thank you for this. Lots of learning in the links you've provided for this septuagenarian.
Pls send me new post
Dude, your humor ? ?
Loved your work.
Hello Sir,
I am Sanjeev Khakre and i from Indore City, India , I am your big follower and i have watch your videos and learnt a lots of excel trick or function and many more . thanks so much for all of your excellent support.
Your excel knowledge is real awesome.
Thanks
Sanjeev
Your work is excellent but pls willing to know more details about the features of microsoft excel
Chandoo Would Access be a better alternative than VB?