With CircleCI you can schedule workflows. This is similar to a cron job that sets the time (hour day week) when your workflow will repeat or run automatically.
Configuration for Scheduling:
https://circleci.com/docs/2.0/configuration-reference/#schedule
Scheduling Workflows:
https://circleci.com/docs/2.0/workflows/#scheduling-a-workflow
NOTE: All times must be scheduled in UTC. Other timezone formats are not supported.
NOTE: Scheduling only supports POSIX crontab syntax. You can read about supported syntax characters on their page here.
http://pubs.opengroup.org/onlinepubs/7908799/xcu/crontab.html