How to set time zone for Shortcut automations on iPad?

I have shortcut automations set up to text my grandchildren every night before they go to bed. However, when I’m traveling to a different time zone or out of the country, of course the iPad picks up the local time so the text is sent inappropriate times, for example, the middle of the night. I don’t see an option to choose a time zone just the time of day. Thoughts?