strange results when calculating variable from varaible filled with calendar /slider value

[curiousfellow]

I have a simple date slider with min and max value and set the format to d-m-y

The value is stored in a variable called v_today

I thought i could calculate other variables based on the stored value

I tried a lot different expressions and formats but I get strange results.

When I add a variable with expression =addyears($(v_today),1) I get strange results.

Please have a look at enclosed qvw and tell me what i am doing wrong

[Gysbert_Wassenaar · Accepted solution]

The AddYears function returns a date. Your variable gets the value of that date, but not the numeric value of that date, but its text representation: 23-10-2018. When you evalutate that value with dollar expansion you get $(23-10-2018) which gives the result of 23 minus 10 minus 2018. That's -2005. If you don't dollar expand it but use it in the Date function you get Date(23-10-2018) which is Date(-2005) which gives the resulting date 4-7-1894. 

So how do you fix that? One way is to create your variable as =num(addyears(v_today, -1)) so that it always gets a numeric value which can be evaluated correctly in a dollar expansion and also works correctly as input for the Date function.

[curiousfellow]

Thank you for your quick answer