TravelAssist™ is a feature of Informant iOS and Android which automatically sets the time zones of events you enter in and out of the travel time. To work, it requires a travel plan with a specific timezone. The timezone is picked by the city you enter so it's easy to set up a trip:

On iOS in Informant go to Settings > Calendars, Triggers, and more > TravelAssist

On Android in Informant go to Settings > TravelAssist

Then to set up your trip, tap on the + button or New

Pick your travel dates/times

Start typing a city name. As you type, Informant contacts a cloud service to search for cities out a database of over 600,000 cities and offers the cities found in a popup menu underneath. 

Pick the city that matches where you are traveling.

Press Done.

You'll now see that trip is set as an event in your calendar view.

When you create a new event after this for the time period you will be on that trip, it will automatically adjust the event time to the new time zone as you travel. That means that an event you create for 9:00am will still be 9:00am when you are in the new time zone.

*Please note, you must have an internet connection for TravelAssist™ to be set up, but you do not need it to work afterwards. The cloud service provides a way for Informant to search for a city and get that city's timezone. If you simply type the name of a city, TravelAssist™ will not accept the typed input because it needs a timezone to go along with it. If a popup with suggestions for the city does not appear there are two possible causes: Your entry is not found in the database; or you do not have internet access. Make sure you have internet access and choose a different city in the same time zone as you will be in.