Hello, all my data are for the end of month. But I have one variable where the data is listed mid month instead. 15.xx. I need to format this into end of month data.

So that if I have for example
...
15.05.1990 4
15.06.1990 5
15.07.1990 6
.....
i need to make a new series with estimated data such as this:
31.05.1990 4.5
30.06.1990 ...
30.06.1900 ...
......

I know of the ipolate function, but not how to implement it for this. Or should I use a different function?