I am trying to calculate from a start and end date where in a span of 2 years (monthly) these dates fall under. For example,
task 1 |start 29.09.2017 | end 30.04.2020 Total= 31.5 (1 for each full month and percentage of the other months)
task 2 |start 15.04.2018 | end 14.04.2020 Total= 24.9 (for april 2018 a value of 0.5 is assigned)
Is this possible to do in Tableau
You could try a DateDiff calculation. Something like below.
DATEDIFF('month',[Start Date],[End Date])
This will give you an integer value of the number of months between two dates.
However, it appears that you already have an integer value assigned to each date part in your data, so it may be simpler to use a SUM() formula in your case.