Function to retrieve current time on ESP8266?

Projects Networking, Protocols, and Devices
10

Now working as basic system.
Questions:

    if (wifiFirstConnected) {
        wifiFirstConnected = false;
        NTP.begin ("pool.ntp.org", timeZone, true, minutesTimeZone);
        NTP.setInterval (63);
    }

What is the purpose of the 4th parameter in begin()?
What is the unit of the setInterval() parameter? milliseconds, seconds, minutes or what?
Is there no way to retrieve the current time from the NTP object following its first sync with an NTP server?
The function getTime() actually runs a connection against the server, when it could calculate current time internally.
Is there no way to have GetDateStr() return the string in ISO format?