When you build a push campaign, you can choose to deliver in the user's local timezone - that is, to stagger delivery so that rather than everyone receiving the message at 4 PM your time, they receive it over the course of the day at 4PM in their own local time, whether they're in London or Boston.
Additionally, Localytics has the unique capability of letting you choose the starting timezone. By default, timezone campaigns begin sending at the International Date Line and proceed west until the end of the day. But certain campaigns benefit from starting in a specific timezone instead, and proceeding for 24 hours afterwards.
For example, if you're scheduling a news update to go out at 9 AM on Tuesday based on something that just happened at 7 AM Tuesday in London, you may want to start that campaign at 9 AM London time and proceed for a full day afterwards, rather than queueing it up for Wednesday and delaying delivery (or trying to send it out Tuesday, but potentially missing Eastern European sends because their 9AM on Tuesday has already passed when you start the campaign).
Or you may want to deliver a notification at 5 PM in the user's local time about a show that goes live at 7 PM - but that show may not be available in Europe until after it goes live in the US. In that case, starting the campaign with the US East timezone makes more sense than starting with the default International Date Line.
Additionally, Localytics calculates campaign audiences immediately before the first timezone's sends; if your uses are particularly latency sensitive, you may want to choose a starting timezone near your primary user base to ensure that audience is as fresh as possible.
When choosing "delivered in the user's timezone," you can select the starting timezone from the dropdown below:
Regardless of what starting time zone you pick, sends will proceed for a full 24 hours, to cover all timezones available.