scheduling backup in heroku command faills
To get this fixed in Windows you should use double quotes instead of singles quotes.
That would be:
heroku pg:backups:schedule DATABASE_URL --at "02:00 America/Los_Angeles" --app sushi
Maybe this could sounds odd but did you change the "sushi" for your app name? I just copy the command and used my app name and the backup is schedule.
This seems to be happening only on Windows. I had exactly the same problem on Windows 7 and was not able to solve it. However, when my friend executed the same command on Linux (for the same application), everything worked without any problems.