Three timing modes
A fixed moment sends to everyone at the same instant. Right for an announcement that must be simultaneous, wrong for a promotion that would reach Sydney at 3 a.m. A local window opens the campaign in each zone when its clock reaches the start hour. A pace spreads the send over time. They combine.
How zones are resolved
Each number maps to a country from its prefix. For countries with several zones, the zone comes from the area code where the numbering plan allows it, and from the country's most populous zone where it does not. Mobile numbers in the United States are the known weak spot: they follow the area code the line was issued in, not where the person lives now.
Edges of the window
Messages not sent when the window closes wait for the next day's window. Quiet hours per country apply inside your window: a 08:00 to 22:00 window still stops at 20:00 in France. Daylight saving is computed in the destination zone at send time, so a campaign scheduled weeks ahead lands at the hour you chose.
Adding a pace
A pace is a ceiling, in messages per minute, or a duration to spread the list over. Use it when replies, calls or clicks land on something with finite capacity. Four hundred messages a minute with a two percent reply rate is eight conversations a minute: know who answers them.
Worked examples
- Flash sale, 40 countries: window 10:00 to 18:00 local, default quiet hours, no pace.
- Appointment reminders: fixed moment per message from your system, transactional flag.
- Re-engagement of 300,000 numbers: window 11:00 to 17:00, pace spread over three days, so the report of day one can fix the list for day two.
Something unclear or out of date? Write to [email protected]; corrections are folded back into the guide and the update date changes.