Weekends, nights and holidays are, most likely, terrible times to get a message across your audience. If your email gets caught up in the inbox clutter that many of us receive each morning when we check our emails, chances are your message will end up in the trashcan.
Know your target. Time your audience. Make sure that your west coast clients or potential customers get your messages during their business hours, same with your east coast clients.
Separate your lists and take advantage of the SCHEDULE option EmailBrain offers. Ohh... and one more tip. Send your list at different times during business hours. One week send it at 10:00 AM, and the next week send it at 2:00 PM. Then go back to your account and analyze the REPORTS & STATS of each campaign. Nothing like trial and error to maximize the open-rates of your message.