How does time zone segmentation improve performance?

Time zone segmentation ensures emails arrive when recipients are likely to read them, not when it's convenient for you to send.

Collect time zone data. Infer from IP address at signup, derive from country or region, or ask directly. IP-based inference is automatic but approximate. Country-level assumptions work for single-timezone countries but fail for large ones like the US, Canada, or Russia.

Send-time optimization. Instead of blasting your entire list at once, stagger sends by time zone. "9am local time" means different absolute times across your list, but the same relative time for each recipient.

Most ESPs support this natively. Look for features called "send time optimization" or "local time sending." You specify the target local time, and the platform handles the scheduling math.

Consider edge cases. What about subscribers without time zone data? Default to your largest audience's zone, or your own. What about daylight saving time transitions? Most platforms handle this automatically, but verify.

Time zone segmentation has limits. You can reach people at the right hour, but you can't guarantee they're checking email. Test whether local time sending actually improves your metrics versus simpler approaches.