To access your Outreach Schedule, go to your Campaign Settings by clicking the chrome wheel at the top right of the campaign in question and click "Outreach Schedule".
Your Outreach Schedule dictates when your outreach emails will go out. You can customize everything including the days your emails will go out, the time in which they'll go out, as well as your Daily Limit. For advanced options see Pausing Outreach (Campaign Level).
Be sure to always “Save” before exiting your settings!