Moment: Remover fuso horário de um objeto moment.js

Duplicar: http://stackoverflow.com/questions/34050389/remove-timezone-from-a-moment-js-object

Conforme o momento irá formatar a data original para ser uma data de fuso horário local. ou seja, 2017-08-02 10:00:00+02:00 será formatado para 2017-08-02 16:00:00+08:00 se o sistema da máquina estiver usando o fuso horário +08:00.

Eu escrevi uma função para formatar a data original ignorando o fuso horário:

/**
 * <strong i="7">@desc</strong> use moment to format a datetime
 * <strong i="8">@param</strong> string|date|timestamp datetime: the datetime to format
   the given datetime can have timezone, and the timezone will be kept in the process of output datetime
   i.e. formate('2017-09-08 11:24:00+08:00', 'D/M/YYYY HH:mm:ss Z') =>  8/9/2017 11:24:00 +08:00, as you see, +08:00 is kept, which is different from moment default behavior
   if timezone has not been given, local timezone will be used.
 * <strong i="9">@param</strong> string formatter: the target format you want to get
 * <strong i="10">@param</strong> string givenFormatter: moment allow developer to define your own formatter, i.e. DD/MM/YYYY HH,mm,ss which is not a statndard time format
 * <strong i="11">@return</strong> string new formatted datetime string
 * <strong i="12">@example</strong>:
   1. format(new Date(), 'YYYY-MM-DD HH:mm:ss')
   2. format(your_date, 'YYYY-MM-DD HH:mm:ss', 'DD/MM/YYYY HH,mm,ss')
 */
export function format(datetime, formatter, givenFormatter) {
  let localTimezoneOffset = timezoneOffset()
  let givenTimezoneOffset = moment.parseZone(datetime).utcOffset()

  if (givenTimezoneOffset !== 0) {
    return moment(datetime, givenFormatter).utcOffset(givenTimezoneOffset).format(formatter)
  }
  else {
    // big problem: we do not know whether timezone has not been given or it is +00:00
    // if its utc time is the same with itself, it means timezone has been given
    let u = utc(datetime, 'YYYY-MM-DD HH:mm:ss')
    let t = moment(datetime).parseZone(datetime).format('YYYY-MM-DD HH:mm:ss')
    if (u === t) {
      return moment(datetime, givenFormatter).utc().format(formatter)
    }
    else {
      return moment(datetime).format(formatter)
    }
  }
}

Código fonte: https://github.com/tangshuang/moment-format

Use esta função para formatar a lógica de formato padrão do momento e ignorar a data. 2017-08-02 10:00:00+02:00 será formatado como 2017/08/02 10:00:00+02:00.

const tmp = moment(valueAsDate).utc(true) - é disso que você precisa, ignora o fuso horário
então você pode usar, por exemplo, como tmp.toISOString() .