Aggregation per day

[limu]

Hello everybody,

I have the following data: 

datetime	date	time	availability
01.01.2020 10:00	01.01.2020	10:00	0.90
01.01.2020 20:00	01.01.2020	20:00	0.70
02.01.2020 10:00	02.01.2020	10:00	0.80
02.01.2020 20:00	02.01.2020	20:00	0.90

I am trying to create a line chart where the dimension x-axis are the dates and the measurement (y-axis) is the avg(availability). Does anyone now how to aggregate the dates?

Thank you in advance!

[Taoufiq_Zarra]

can you share the expected output ?