Populates a Google calendar titled "Rise and Fall", using the a free sunrise and sunset API from a specified date range for San Francisco.

populateCalSunRiseNSet.gs

/**
 * EXAMPLE: https://developers.google.com/calendar/api/quickstart/apps-script 
 * @see https://developers.google.com/calendar/api/v3/reference/events/list
 * 
 * 
 * Sun rise and set API: https://sunrise-sunset.org/api 
 * 
 */
function populateCalSunRiseNSet() {

  /*
   *  === GLOBAL VARIABLES ===
   */

  // The Calendar to set the events in:
  // This is an ARRAY, that should only have one element! i.e. one Calendar
  var riseFallCal = CalendarApp.getCalendarsByName('Rise and Fall');
  // Logger.log('Found %s matching calendars.', riseFallCal.length);
  // Logger.log(riseFallCal[0].getName());


  // Sun Rise and Set Location
  // location reference
  // https://sunrise-sunset.org/search?location=San+Francisco
  var latitude = '37.7790262';
  var longitude = '-122.419906';

  var today = new Date();
  Logger.log('The date is ' + Utilities.formatDate(today, 'America/Los_Angeles', 'yyyy-MM-dd'));
  // https://developers.google.com/google-ads/scripts/docs/features/dates

  // The last day where for the event to be set
  // The monthIndex for december is 11
  var endDate = new Date(2022, 11, 32);
 
  /*
   *  ^^^ GLOBAL VARIABLES ^^^
   */


  /*
    Takes a date object
    Makes a call to sunset/sunrise API
      retrive JSON
      parse JSON into usable object
    Returns JSON as parsed data
  */
  function getDayData(date){

    var url = 'https://api.sunrise-sunset.org/json'
    + '?lat=' + latitude
    + '&lng=' + longitude 
    + '&date=' + Utilities.formatDate(date, 'America/Los_Angeles', 'yyyy-MM-dd')
    + '&formatted=0';

    var response = UrlFetchApp.fetch(url, {'muteHttpExceptions': true});
    Logger.log("getDayData json call: \n" + response);

    var json = response.getContentText();
    return JSON.parse(json); //data
    // Logger.log(data.results.sunrise);
  }

  /* 
    This is to split the date from the time without the timezone
    Appends UTC at the end of string
  */
  function timeExtract(input) {
    var timeWithZone = input.split("T");
    var justTime = timeWithZone[1].split("+");
    // Logger.log(justTime[0]);
    return justTime[0];
  }

  /*
   * Where actual work is done! 
   */
  try {

    for (var i = today; i < endDate; i.setDate(i.getDate() + 1)) {
        Logger.log("Setting the event for: "+ i + '\n');

        var data = getDayData(i);

        // Redudant variables:
        // var nauticalTwilightBegin = data.results.nautical_twilight_begin;
        // var sunriseTime = data.results.sunrise;

        // This is to split the date from the time without the timezone
        var nauticalTwilightBeginExtract = timeExtract(data.results.nautical_twilight_begin);
        var sunriseTimeExtract = timeExtract(data.results.sunrise);

        // THIS part should be a function
        //
        var riseStartTime =  Utilities.formatDate(today, 'America/Los_Angeles', 'MMMM dd, yyyy ') + nauticalTwilightBeginExtract + ' UTC' ;
        var riseEndTime = Utilities.formatDate(today, 'America/Los_Angeles', 'MMMM dd, yyyy ') + sunriseTimeExtract + ' UTC' ;
        // Logger.log('Start ' + riseStartTime + ' End ' + riseEndTime);
        //
        // 

        
        // Logger.log(riseFallCal[0].getName());
        // Logger.log(riseFallCal[0].getId());

        // CREATE SUNRISE EVENT! (THIS SHOULD BE A FUNCTION -- to avoid redundancy sake ... )
        var event = CalendarApp.getCalendarById(riseFallCal[0].getId()).createEvent('Sunrise 🌅',
        new Date(riseStartTime),
        new Date(riseEndTime));
        Logger.log('SUNRISE Event ID: ' + event.getId());


        // Redudant variables:
        // var sunsetTime = data.results.sunset;
        // var nauticalTwilightEnd = data.results.nautical_twilight_end;

        // This is to split the date from the time without the timezone
        var sunsetTimeExtract = timeExtract(data.results.sunset);
        var nauticalTwilightEndExtract = timeExtract(data.results.nautical_twilight_end);

        var settingStartTime =  Utilities.formatDate(today, 'America/Los_Angeles', 'MMMM dd, yyyy ') + sunsetTimeExtract + ' UTC' ;
        var settingEndTime = Utilities.formatDate(today, 'America/Los_Angeles', 'MMMM dd, yyyy ') + nauticalTwilightEndExtract + ' UTC' ;
        Logger.log('Start ' + riseStartTime + ' End ' + riseEndTime);
        
        // CREATE SUNSET EVENT!
        var event = CalendarApp.getCalendarById(riseFallCal[0].getId()).createEvent('Sunset 🌇',
        new Date(settingStartTime),
        new Date(settingEndTime));
        Logger.log('SUNSET Event ID: ' + event.getId());
       
    }


  } catch (err) {

    // TODO (developer) - Handle exception from Calendar API
    Logger.log('Failed with error %s', err.message);


  }
}