There is no such thing as an "optimal time" for sending push notifications.
A lot depends on the industry in which you work.
If you're in the B2B arena, bear in mind that the industry in which your clients operate might influence when you send push notifications.
In fact, even within the same business, a lot may change.
Here's a brief rundown of when to send push alerts:
9 a.m., 12 p.m.-2 p.m., 9 p.m.-11 p.m.
11 a.m. to 12 p.m., 7 p.m. to 8 p.m
Housewives in their forties and fifties
12 o'clock 2 p.m., 9 p.m., and 11 p.m.
9 a.m. to 12 a.m., 7 p.m. to 2 a.m
Again, there's no certainty any optimal moment for your company to send out push notification. This timesheet is intended to assist you in getting started. Take this chart with a grain of salt if you're looking for a push notification timetable.
In either case, you should obviously categorize your customers before sending push alerts.
If this seems like a good concept to you, you should use Swipecart to optimize your push notification approach by creating segments.