Yes, Action Items in your Sequences are subject to your sending schedule and are dictated by the Wait Time between steps.
In the below example, the Wait Time is 5 minutes. That means if there is no reply after 5 minutes, the action item takes effect.
Please note, if you send an automatic email on Monday at 4.57pm and your Sending Schedule is Monday-Friday, with a Wait Time of 5 minutes, your action item won’t take effect until Tuesday morning at 9.02am. For more information about sequence schedules, please refer to the "Create and Edit Sequence Sending Schedules" article.