How to convert X-axis in a Gannt chart to numbers

[hans L]

I have developed a Gantt chart that shows dates as tick marks along the
X-axis. These dates con be converted to a general number format but I want
to manipulate these numbers so that the tick marks represent the durations
between the dates. If, for instance, my first three tick marks read
4/1/2010, 5/1/2010 and 5/31/2010, I want to see the values 0, 30, 60 etc. to
indicate the increments between the tick marks. Thank you for your help.

 

[hans L]

Unfortunately, it's not that simple. My data looks like this:
Task Start Duration Finish
A 4/12/10 60 6/11/10
B 5/3/10 85 7/12/10
C 6/14/10 63 8/16/10
By defining he X-axis as starting on 4/1/10 and ending at, say, 7/5/10 and
defining tick marks at every 30 days, the chart generates the dates 4/1/2010,
5/1/10, 5/31/10 and 6/30/10, etc. So, it's the tick marks that I want to
convert from a date format to read 0, 30, 60 and 90, etc. This way the chart
would become a generic chart independent of start and finish dates.
Thanks

 

[Jon Peltier]

It is that simple. In the worksheet, subtract 4/12/10 from all dates, so
the start values for the three tasks are 0, 21, and 63.

I think this is what David has suggested.

- Jon

 

[hans L]

I'm afraid I didn't make myself clear. I do not want to convert the dates of
the table as numbers but the tick marks in the graph so they appear as 30 day
increments or 25, or 20 as I choose. I used an example of a Gannt chart that
came from your blog. Ideally, the tick marks would show as vertical lines
so that the reader of the graph gets a good sense of the duration of the
tasks, not when they take place. I extract the data from other software and
that helps me to create the graph.

 

[Jon Peltier]

Can't you set a major tick spacing of 30 days (or whatever you want)?

- Jon

 

[hans L]

I did set the spacing at 30 days. If I set the format at "General Number" it
reads 40269, 40299 etc. So, how do you set a custom format that subtracts a
certain number of days from what is displayed?

 

[hans L]

You offered a solution in your first e-mail. This forum sometimes comes up
with more than one solution. You didn't specifically say that it could not
be done through formatting. Your reference to my command of the English
language, or implied lack thereof, was uncalled for.

 

[Jon Peltier]

Formatting changes the appearance of a number. Only formulas change the
values. Several times it was suggested that you subtract a starting
date, to produce a number of elapsed days. Nobody suggested a formatting
solution, because it is not possible.

David's comment was a bit harsh.

- Jon

 

[Herbert Seidenberg]

Excel 2007 Gantt chart
Edit horizontal axis.
It caan be done with macros.
However, you kant squeeze 85 days between
5/3/10 and 7/12/10.
http://c0718892.cdn.cloudfiles.rackspacecloud.com/05_15_10.xlsm
Pdf preview:
http://www.mediafire.com/file/jnmiod1nlbj/05_15_10.pdf