/**
 * Move events with a given title from your primary calendar to another calendar.
 * You must enable the Calendar Advanced Service:
 * https://developers.google.com/apps-script/guides/services/advanced#enabling_advanced_services
 */
function moveEvents(eventTitle, fromCalendarName, toCalendarName) {
  var fromCalendarId = CalendarApp.getCalendarsByName(fromCalendarName)[0].getId();
  var toCalendarId = CalendarApp.getCalendarsByName(toCalendarName)[0].getId();
  
  var now = new Date();
  var oneYearAgo = new Date(now);
  oneYearAgo.setYear(oneYearAgo.getYear() - 1);

  var pageToken = null;
  do {
    var results = Calendar.Events.list(fromCalendarId, {
      q: eventTitle,
      pageToken: pageToken
    });
    results.items.filter(function(event) {
      return event.summary == eventTitle;  
    }).forEach(function(event) {
      Calendar.Events.move(fromCalendarId, event.id, toCalendarId);
      console.log('Moved event ' + event.id);
    });
    pageToken = results.nextPageToken;
  } while (pageToken)
}

function test() {
  moveEvents('Gym', 'Medical', 'Exercise');
}