How would I adjust my Python code for a nested .JSON tree (Python dictionary) to include multiple keys?

In my current code, it seems to only take into account one value for my Subject key when there should be more (you can only see Economics in my JSON tree and not Maths). I've tried for hours and I can't get it to work.

Here is my sample dataset - I have many more subjects in my full data set:

ID,Name,Date,Subject,Start,Finish
0,Ladybridge High School,01/11/2019,Maths,05:28,06:45
0,Ladybridge High School,02/11/2019,Maths,05:30,06:45
0,Ladybridge High School,01/11/2019,Economics,11:58,12:40
0,Ladybridge High School,02/11/2019,Economics,11:58,12:40
1,Loreto Sixth Form,01/11/2019,Maths,05:28,06:45
1,Loreto Sixth Form,02/11/2019,Maths,05:30,06:45
1,Loreto Sixth Form,01/11/2019,Economics,11:58,12:40
1,Loreto Sixth Form,02/11/2019,Economics,11:58,12:40

Here is my Python code:

timetable = {"Timetable": []}
with open("C:/Users/kspv914/Downloads/Personal/Project Dawn/Timetable Sample.csv") as f:
    csv_data = [{k: v for k, v in row.items()} for row in csv.DictReader(f, skipinitialspace=True)]

    name_array = []
    for name in [row["Name"] for row in csv_data]:
        name_array.append(name)
    name_set = set(name_array)

    for name in name_set:
        timetable["Timetable"].append({"Name": name, "Date": {}})

    for row in csv_data:
        for entry in timetable["Timetable"]:
            if entry["Name"] == row["Name"]:
                entry["Date"][row["Date"]] = {}
                entry["Date"][row["Date"]][row["Subject"]] = {
                    "Start": row["Start"],
                    "Finish": row["Finish"]
                }

Here is my JSON tree: