Why is date being written as float in csv file

Question

I am trying to save some data in csv file. Some of the date formats are changed to float.

This is data:

results = [{'Event ID': 15, 'Time Start': '2022/05/04 17:75', 'Time End': '2022/05/04 18:00''}
{'Event ID': 15, 'Time Start': '2022/05/04 18:00', 'Time End': '2022/05/04 20:50'}
{'Event ID': 0, 'Time Start': '2022/05/06 16:50', 'Time End': '2022/05/06 17:00'}
{'Event ID': 4, 'Time Start': '2022/05/09 15:00', 'Time End': '2022/05/09 15:50'}
{'Event ID': 14, 'Time Start': '2022/06/13 07:75', 'Time End': '2022/06/13 08:00'}
{'Event ID': 4, 'Time Start': '2022/06/15 09:00', 'Time End': '2022/06/15 10:50'}
{'Event ID': 14, 'Time Start': '2022/06/16 02:75', 'Time End': '2022/06/16 03:00'}]

The code to save it as csv is as shown below

 csv_columns = ['Event ID', 'Time Start', 'Time End']
    csv_file = "ets_results.csv"
    try:
        with open(csv_file, 'w', newline='') as csvfile:
            writer = csv.DictWriter(csvfile, fieldnames=csv_columns)
            writer.writeheader()
            for data in results: 
                print(data)
                writer.writerow(data)
    except IOError:
        print("I/O error")

The output of the csv file looks like this