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.
17 Responses to “Custom Number Formats – Colors”
You are right, Chandoo. I was playing with the colour numbers last week and some of them don't appear different from each other. Others are totally different from yours.
@Duncan
Each version of Excel, post 2003, renders colors slightly differently
Different language versions may also have different default color palettes
Hello in french
excel 2010
colo1 = couleur1 = black
[couleur1]; [couleur2]; etc..
@Hui, thank you very much again for this great post.
However - under Excel 2007, Hungarian version your solution does not work with color names. I've tried both English and Hungarian names, but drops an error message "not valid formats"
Do you have any idea how to solve this issue?
thanks in advance
@Andras
Without a Hungarian version of Excel 2003 I don't think I can assist
Have you tried using the colour numbers? I couldn't get the names to work (despite using an english version of excel). but it did work with the numbers though. I left out the "u" and was easily able to produce burgundy using [color9]
Here a possible solution: find an English version of Excel, write there the formats using English names, then open the file in the Hungarian version and see the translation.
In Excel 2007 I can't get the colour names to work e.g Sea Green but the numbers do e.g color3 - colour3 does not work so I must bow to the country that has stolen my language (ha ha!)
Hey chandoo, nice Tip!
Wouldn't be easier just apply some conditional formatting for negative numbers and another for positive numbers? Or there's some cases that you can't do that?
Unfortunately the TEXT function doesn't color the cell as number formatting does.
Hi Hui,
Great post Sir, love the new way of formatting with color numbers.
I am using 2007, and it leads me to the last color number 56.
Thanks Hui.
[…] explains how to set up custom number formats with a wide array of […]
Thanks Hui - works a treat!
Thank you, very helpful.
Trying to figure out if it is possible to apply color only to a part of the cell?
E.g. I have a value formatted as Accounting with a currency symbol.
Those I find somewhat distracting though necessary. If I could make them less obtrusive by coloring them gray while the number would stay black, that would be great. Tried tinkering with the format string, but didn't get the desired result. Single color for complete cell value works, but coloring just part of it could not be achieved. Maybe somebody managed that?
Exactly what I was looking for - thank you!
colour in the Australian doesn't work - we have to go American and no problem.
I always thought is was 56 colours notice you have 57. Cool.
thanks
Analir Pisani
Customised Microsoft Office Training Specialist
Sydney - Australia
http://www.azsolutions.com.au
Thank You!