If you are getting the “Outside of Send Timeframe” message after you have scheduled a campaign, this means that you are attempting to send the campaign out the time frame that was set up for your company. Example, your company may have enabled this feature to only allow messages to be sent out between 9:00 to 21:00 EST.
Send Time windows are set to promote a positive candidate response rate for messages that are being sent. If a candidate receives messages too early or too late then you may not have a positive response.
If you have manager level access then you can change this for the company if they need to. If you do not have manger level access you can reach out to your manager to see if it can be changed.