Hi Sebastian,
first of all, welcome to the community! We are always happy to receive and respond to your questions.
Based on what you are asking I wrote a comprehensive guide on how to retrieve results from the API in python, using the pagination features and write them into a CSV for further processing by other tools here:
To specifically answer your question notice the line which converts the epoch timestamp in milliseconds into a human readable timestamp here:
'ts': datetime.fromtimestamp(result['attributes']['ts'] / 1000).strftime('%Y-%m-%d %H:%M:%S'),
Let me know if you have any other questions regarding this or the API in general.
Thanks,
Panickos