This post builds on earlier discussion, How many hours did Johnny work? I recommend you to read that post too.
Lets say you have 2 dates (with time) in cells A1 and A2 indicating starting and ending timestamps of an activity. And you want to calculate how many workings hours the task took. Further, lets assume,
- Start date is in A1 and End date is in A2
- Work day starts at 9 AM and ends at 6PM
- and weekends are holidays
Now, if you were to calculate total number of working hours between 2 given dates, the first step would be to understand the problem thru, lets say a diagram like this:
We would write a formula like this:
=(18/24-MOD(A1,1)+MOD(A2,1)-9/24)*24 + (NETWORKDAYS(A1,A2)-2)*9
See the above illustration to understand this formula.
Now, while this formula is not terribly long or ineffective, it does feel complicated.
May be we can solve the problem in a different way?!?
Michael left an interesting answer to my initial question, how many hours did Johnny work?
Pedro took the formula further with his comment.
The approach behind their formulas is simple and truly out of box.
Instead of calculating how many hours are worked, we try to calculate how many hours are not worked and then subtract this from the total working hours. Simple!
See this illustration:
So the formula becomes:
Total working hours between 2 dates – (hours not worked on starting day + hours not worked on ending day)
=NETWORKDAYS(A1,A2)*9 - (MOD(A1,1)-9/24 + 18/24 -MOD(A2,1))*24
After simplification, the formula becomes,
=NETWORKDAYS(A1,A2)*9 - (MOD(A1,1) -MOD(A2,1))*24 -9
=(NETWORKDAYS(A1,A2)-1)*9 +(MOD(A2,1)-MOD(A1,1))*24
Sixseven also posted an equally elegant formula that uses TIME function instead of MOD()
=(NETWORKDAYS(B3,C3)*9) - ((TIME(HOUR(B3),MINUTE(B3),SECOND(B3))-TIME(9,0,0))*24) - ((TIME(18,0,0)-TIME(HOUR(C3),MINUTE(C3),SECOND(C3)))*24)
Download the solution Workbook and play with it
Click here to download the solution workbook and use it to understand the formulas better.
Thanks to Pedro & Michael & Sixseven & All of you
If someone asks me what is the most valuable part of this site, I would proudly say, “the comments”. Every day, we get tens of insightful comments from around the world teaching us various important techniques, tricks and ideas.
Case in point: the comments by Michael, Pedro and Sixseven on the “how many hours…” post taught me how to think out of box to solve a tricky problem like this with an elegant, simple formula. Thank you very much Michael, Pedro, Sixseven and each and every one of you who comment. 🙂
Have a great weekend everyone.
PS: This weekend is my mom’s birthday, plus it is a minor festival in India. So I am going to eat sumptuously, party vigorously and relax carelessly. Next week is going to be big with launch of excel school 3.
PPS: While at it, you may want to sign up for excel school already. The free lesson offer will vanish on Wednesday.
13 Responses to “Gantt Box Chart Tutorial & Template – Download and Try today”
Hi Chandoo
As one of your students I have followed your detailed example through with great success. However, Excel is acting in an unexpected way and I wonder if you could take a look?
http://cid-95d070c79aef808e.office.live.com/self.aspx/.Public/Gantt%20Box%20Chart.xlsm
On my version, I have to type 40239 (Which equates to 2 Mar 2010) to get the chart to display 31 May 2010 (which should be 40329)!!??
Have I done something wrong or is Excel acting up?
Thx
Oli
PS Your example file in 2007 displays correctly.
Hi,
I like this idea a lot, but I agree the name is a little drab.
As an American I may just be seeing things, but to me the combination of lines and bars on your chart looks like a bunch of cricket bats.
Maybe you could work that into a catchier name. 🙂
Cheers!
Here is some code I use to keep the axis synched.
It may be useful to some of your readers
It is based on a comment I saw on Daily Dose of Excel.
Function SynchGanttAxis(Cname, lower, upper)
'Sets the X min and X max for Category axis
Application.Volatile
On Error Resume Next
'
'Top Horizontal Axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlCategory, 1)
.MinimumScale = lower
.MaximumScale = upper
End With
'Bottom Horizontal Axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlValue, 2)
.MinimumScale = lower
.MaximumScale = upper
End With
End Function
Function SynchVerticalAxis(Cname, lower, upper)
Application.Volatile
On Error Resume Next
' Excel 2007 only
'Right hand vertical axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlValue, 1)
.MinimumScale = 0
.MaximumScale = upper
End With
End Function
@Oli.. Can you check your file again.. I see 40329...
@Dave: Even I saw things.. the bars actually looked like lollipops. How about calling this lollipop chart - now that would be yummy and goes along the tradition of naming charts after eatables (bar, pie, donut...)
@Bob: Superb stuff... thanks for sharing 🙂
Hi Chandoo
This looks really good and I think it can also be applied to show project phases / milestones.
Question: Thinking further could this be amended to display a project lifecycle (Idea through to Implementation say 7 phases) on one bar / row? Just imagine 20 projects within a programme all on one chart one bar each showing their respective lifecycle stages i.e. on one page.
Idea: As the Gantt Box Chart this is quite intensive to set up re formatting etc how about the added extra of once you have completed this to "Save as template" i.e. saves the formatting and layout of the chart as a template so you can apply to future charts. Simple to do and will save the time formatting etc again and again and again.
Therefore tip: Click on your chart demo and then click on Save As template icon (2007) - edit file name and click on save. Ready to use / apply via Templates in Change Chart Type window.
Thanks and be very interested if the lifecycle question can be resolved
Mike
How embarrassing.
I was obviously suffering from numerical dyslexia. I was one of those days.
@Mike H: You can easily make this chart to work like a generic project lifecycle plan chart. All you have to do is,
1. in a separate sheet define the steps of lifecycle and various dates in a table (with 5 columns for each of the projects you have).
2. now use a control cell to input the project name you want to show in the chart
3. based on the input, use OFFSET Formulas to get the correct data
4. Rest is same as the tutorial above
For more info on the dynamic charting visit http://chandoo.org/wp/tag/dynamic-charts/ and http://chandoo.org/wp?s=OFFSET
Your solution is really smart but in the en Excel isn't meant to do stuff like this. I, as a former PM, always thought is was frustrating that you had to do stuff like this for something simple like a Gantt chart. So I built Tom's Planner. And would like to plug it here. I think it really solves the problem you are trying to solve in the most efficient way. Check out http://www.tomsplanner.com for a free account or play around with the demo.
Hi there,
Chandoo - this is really a very nice and helpfull chart - I adopted it, so I can report a forecast or the delay of a certain task (coming from my role as an auditor for projects).
One topic I´m currently struggeling with: I do have a project lasting for lets say 12 month. For a management reporting, I want to have kind of snapshot, lets say one month back and 2 month in the future. I tried with the offset formula, but failed. Any idea?
Thx
Lopi
[...] Ein viel geliebter Klassiker ist die Erstellung von GANTT-Diagrammen mit Excel. Wir hatten das Thema wiederholt schon hier. Chandoo.org hat sich mal wieder mit einer neuen Variante hervorgetan: Das GANTT-Box-Chart. [...]
[...] [...]
Hi Chandoo - fantastic xls. One thing I can't figure out how to do is adjust the alignment of the vertical axis. I would like to left align so that I could indent to represent sub tasks. Can that be done? Or is there a better way?
I've been trying to work out if there's a way to show weekends on the graph. The closest thing I've got is to add them on a secondary axis, but then I haven't been able to keep both axis lined up together! Any ideas?
Following on from this - is it possible to show things like holidays?