When you are creating a survey, you can choose how often it would be asked, on what day of the week and at what time of the day.
Morning surveys are asked at 9am and afternoon surveys are asked at 5pm of the timezone of the teammate who created or last edited the survey.
So if you are based in New York and choose the survey to run once a month on Monday mornings - it will trigger first time next Monday at 9am, Eastern time. And than repeat on Mon, 4 weeks later.
You'll be able to see the exact date it will be sent on the survey page: