This script produces a ./data/speedtest.csv file with a line of speedtest results added for each invokation like this:
Date Time Ping (ms) Download (Mbit/s) Upload (Mbit/s)
2020-06-13 12:30:25 39.344 62.84 5.01
2020-06-13 12:45:25 37.155 71.26 7.29
2020-06-13 13:00:26 36.38 69.76 6.67
2020-06-13 13:15:25 35.591 84.68 7.18
2020-06-13 13:30:25 34.531 79.09 7.08
2020-06-13 13:45:25 36.315 111.46 7.32
2020-06-13 14:00:25 35.602 66.97 7.16
2020-06-13 14:15:25 35.74 64.98 7.12
Load the image from Docker Hub and run the container providing your timezone:
docker run -e TZ=Europe/Berlin -v ${PWD}/data:/data --rm abargstaedt/speedtest