changes the date and time of a strava gpx
pip install -r requirements.txt
just run the script, it will ask you to input the filename to the gpx files. then it will ask you to input a date and time in [YYYY-MM-DDThh:mm:ssZ] this format (example: 2020-12-12T16:30:03Z)
the avg speeds and activity length will remain the same, but the start time will change and all the others will follow.
will not work on multi-day activities may mess up the times