You want to find out how much of your Free Dyno hours quota you've used this month.
You can monitor your Free Dyno Hours quota and usage in your Heroku Dashboard or by using the Heroku CLI. Usage metrics are not live and may be delayed up to one day.
Using the Heroku Dashboard
Visit your Billing page: https://dashboard.heroku.com/account/billing
Using the Heroku CLI
Option 1: Show usage in hours
$ heroku ps -a app-name Free dyno hours quota remaining this month: 799h 43m (79%) Free dyno usage for this app: 200h 16m (20%)
Option 2: Show usage in seconds
$ heroku user:info . . . account_quota: 3600000 quota_used: 614439
WARNING: Starting November 28, 2022, free Heroku Dynos, free Heroku Postgres, and free Heroku Data for Redis plans will no longer be available. If you have apps using any of these resources, you must upgrade to paid plans by this date to ensure your apps continue to run and retain your data. Eligible students can apply for platform credits through our new Heroku for GitHub Students program. See our blog and FAQ for more info.