• Thanks @Ollie and @DamianMontero for your answers, I appreciate!

    Do you think I could use a Google Apps Script function to get the daily calendar (as shown here https://www.youtube.com/watch?v=sm1-l5-z3ag
    ) and then call the script from Espruino?

    I tried this:

    var WIFI_NAME = "WIFI_NAME";
    var WIFI_OPTIONS = { password : "WIFI_PASSWORD" };
    var GsToken='YOUR GOOGLE APPS SCRIPT TOKEN HERE';
    
    var wifi;
    
    function getCalendar()
    {
      var options = {
        host: 'https://script.google.com',
        port: '443',
        path:'/macros/s/'+GsToken+'/exec',
        protocol: "https:",
        method:'GET',
        headers: {
          "Content-Type":"application/x-www-form-urlencoded"
        }
      };
    
      console.log("Connecting to Google");
      require("http").request(options, function(res)  {
        console.log("Connected to Google");
        var nRecv = 0;
        res.on('data', function(data) { nRecv += data.length; });
        res.on('close', function(data) {
          console.log("Google connection closed, "+nRecv+" bytes received");
          setTimeout(getCalendar, 10000); // once every 10 seconds
        });
      }).end();
    }
    
    function onConnected(err) {
      if (err) throw err;
      wifi.getIP(function(e,ip) {
        console.log(ip);
        getCalendar();
      });
    }
    
    var Inited=false;
    function Init()
    {
      if(!Inited)
      {
        Inited=true;
        wifi = require("Wifi");
        wifi.connect(WIFI_NAME, WIFI_OPTIONS, onConnected);
      }
    }
    function onInit() {
      setTimeout("Init();",1000);
    }
    
    Init();
    

    The console output is

     ____                 _
    |  __|___ ___ ___ _ _|_|___ ___
    |  __|_ -| . |  _| | | |   | . |
    |____|___|  _|_| |___|_|_|_|___|
             |_| espruino.com
     2v04 (c) 2019 G.Williams
    Espruino is Open Source. Our work is supported
    only by sales of official boards and donations:
    http://espruino.com/Donate
    Flash map 512KB:256/256, manuf 0xef chip 0x4015
    >
    {
      "ip": "192.168.43.173",
      "netmask": "255.255.255.0",
      "gw": "192.168.43.1",
      "mac": "18:fe:34:f5:6a:a9"
     }
    Connecting to Google
    >
    

    Then nothing happens. I think I am pretty close to have a solution not based on a third party service, but, well, it doesn't work as is... I don't know if ESP8266 can do https requests directly or if I need to use some kind of HTTPSRedirect library, used on the Arduino world...
    If anyone has any hints to help me go a step further, that would be awesome :-)

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