gist for generating a fake data to help the question: https://www.reddit.com/r/dataengineering/comments/12cehg3/alternative_to_excel_for_large_data_processing/

generate_fake_data_for_reddit.py

import random

months = 3
every_n_seconds = 5

points = []
for i in range(months * 30 * 24 * 60 * 60 // every_n_seconds):
    points.append([i, random.randint(1, 100)])

with open("data.csv", "w") as f:
    f.write("time,value \n")
    for point in points:
        f.write(f"{point[0]},{point[1]} \n")

print("Done!")