How to record Web form entry date and time

Hi,

I am building a Web form to collect some data from users and I want to record the creation time of each form entry.

I created a field with type "datetimenotz" in the schema and I have issues storing the datetime value into it.

May I know what is the expected input type and format of the SQL data type "datetimenotz"?

JS script to run after form submission and before Storage:

function getUTCDate() {
    var date = new Date(Date.now());
    return pad("00", date.getUTCDate()) +
      '/' + pad("00", (date.getUTCMonth() + 1)) +
      '/' + date.getUTCFullYear() +
      ' ' + pad("00", date.getUTCHours()) +
      ':' + pad("00", date.getUTCMinutes()) +
      ':' + pad("00", date.getUTCSeconds());
  }
  function pad(pad, str) {
    if (typeof str === 'undefined') {
      return pad;
    } else {
      return (pad + str).slice(-pad.length);
    }
 }
 ctx.my_schema.@datetime = getUTCDate();

Error message:

TIM-030009 Date '05/04/2018 05:55:17': invalid character at position 5 ('4') Invalid type for value '05/04/2018 05:55:17' from element '@datetime' (document of type 'somenamespace:my_schema'). XSV-350023 Unable to save document of type 'somenamespace:my_schema'. SOP-330011 Error while executing the method 'Write' of service 'xtk:persist|xtk:session'.

Source schema:

<attribute advanced="false" label="datetime" name="datetime" sqlname="datetime"
               type="datetimenotz"/>