Matching Timestamps

Hello,

I am new to the forum, but i'd like to get some help with powerbi. We are struggeling to match datasets to show the correct data.

I will try to explain it as good as possible;

We have multiple datasets in powerbi that sometimes have a different timeformat;

First source is a prognosis that shows data per month; So 1-1-2023 is a prognosis for januari 2023. The key is the relationship between different projects. This dataset shows a prognosis for rougly 20 keys for evrey month of the year.

The second data source gives us production data per day, per key

If i want to visualise:

Montly prognosis (from first source) vs Montly production data (from second source) i run into troubles. 
Somehow i dont know how to match the timestamps. For example the second datasource should sum all the dates of the different days of the month and sums that to a total.

To visualise: Monthly Production data vs Montly prognosis. 
I have been trying different stuff to visualise this but i cant figure it out. 

Can someone help me with this?