Annual gift upgrade and downgrade

[MarcoGemini11]

Dear Community,

how can I calculate annual gift upgrade and downgrade?

Thank you for your time

[edwin]

you will need to supply more information than that for someopne to help you,  sample data and expected output would be most useful 

[MarcoGemini11]

For example i want to calculate the retained gifter from a current time period that increased his giving this year. 

Therefore I have to calculate the number of donors who have increased their donation this year to the previous year and I wanted to know if there was a formula to calculate it

[edwin]

in other words you have a measure that changes with the date and you want to compare YTD and prior YTD.

it is the same pattern as this one:

https://community.qlik.com/t5/New-to-Qlik-Sense/how-to-calculate-previous-year-sales-till-current-ye...

simple way is to calculate the date boundaries:
today's date (this can be dynamic but for illustration purposes stay with today's date)
start of the year

today's date shifted one year back - you can just add -1 year
start of year of today's date shifted one year back (similar calculation -1 year)

then you frame your expressions using those 4 dates:

YTD = your measure with the set analysis dates >=start of year <=today's date

PTD = your measure with the set analysis dates >=start of year last year <=today's date shifted last year 

[MarcoGemini11]

OK. In this way i can measure the difference gift value between two years. But this is one part of my question.

In the second part i have necessity to count the number of gifter that have increased their gift value.

So i want to set a variable which  based on the increase of  the value of the gift, counts the number of donors who have increased this value.
in this way I calculate the number of donors who have increased the value of their donation compared to the previous year