trim Google Location History to points during a specified time window and view them as a heatmap

instructions.txt

Go to https://takeout.google.com/settings/takeout
"Select None"
Scroll down to "Location History" and select that
Scroll to the bottom, click next, and download the file
Extract the LocationHistory.json

Convert the start and end times that you're interested in to milliseconds since epoch (epoch * 1000) and use them in the comparisons below

Use this jq filter pipeline to match only the timestamps that are within the selected time range, and export that to a file
jq '{"locations" : .locations | map(select(.timestampMs | tonumber >= 1458889200000)) | map(select(.timestampMs | tonumber <= 1459796400000)) }' Takeout/Location\ History/LocationHistory.json > trip.json

Use https://theopolis.me/location-history-visualizer/ to see the heatmap from the trip.json file