Your wish is my challenge…
#!/bin/sh
# from https://www.beeminder.com/api/v1/auth_token.json
AUTH_TOKEN=your_token
USER=your_username
for GOAL in $( curl https://www.beeminder.com/api/v1/users/$USER.json?auth_token=$AUTH_TOKEN | sed -e 's/[^[]*//; s/^.//; s/].*//; s/[",]/ /g' )
do
echo $GOAL
curl -X PUT -d '{"tmin":"2016-01-01"}' https://www.beeminder.com/api/v1/users/$USER/goals/$GOAL.json?auth_token=$AUTH_TOKEN --header "Content-Type: application/json" > /dev/null
done
Using the undocumented tmin
field in the API.