Calculate days to reach a target

Hi Everybody,

In the attached sample, I would like to show the number of days that it took to reach the first $1000 of sales, then the number of days to reach the 2nd $1000 of sales, 3rd $1000 etc.

I would like to find out if the speed at which we are making $1000 of sales is getting faster or slower.

I suspect it might require a separate calculated field for each bucket ie. First $1000, 2nd $1000 etc.

Can anybody help me achieve this in Tableau?

Many thanks,

Matt