We ran a 30-day experiment with one of our customers: identical message, identical customer base, identical frequency — only the send window changed.
The 9-11am window beat the 7-9pm window by 1.8x on response rate, and beat a 12-2pm window by 2.4x. Our hypothesis is that morning send windows catch customers when they are still planning their day, before they are pulled into work or family.
Weekends performed 22% worse than weekdays for service businesses. The inverse is true for retail: weekends can outperform weekdays for restaurants and entertainment.
Quiet hours matter. Buytena will never send between 9pm and 8am local time, and we will not send a third reminder inside 48 hours of the second.