Question

我有一个POSIXct变量，读取2016-12-15 20:11:29 PST，但PST不正确。它实际上应该是2016-12-15 20:11:29 GMT

我需要使时区正确，GMT，然后我需要将其转换为纽约时间

所以我得到2016-12-15 20:11:29太平洋标准时间。这真的应该是2016-12-15 20:11:29 GMT然后我需要将2016-12-15 20:11:29转换为GMT到“America / New_York”所以最终结果将是16:11:29 America / New_York，因为纽约时间是格林尼治标准时间之后。

我尝试了很多方法，但无法让它发挥作用。有什么想法吗？

bool isstoreTapped = false;
  bool iskoleksiTapped = false;
  private void loginBtn_Click(object sender, RoutedEventArgs e)
  {
      loadingLogin.IsActive = true;
      FailedMessage.Visibility = Visibility.Collapsed;
      ProsesLogin();
      if(isstoreTapped==true)
      {
          this.Frame.Navigate(typeof(Store));
      }
      if(iskoleksiTapped==true)
      {
          this.Frame.Navigate(typeof(koleksibuku.KolesiPage));
      }

  }

 private async void ProsesLogin()
        {
            FailedMessage.Visibility = Visibility.Collapsed;
            loadingLogin.IsActive = true;
            try
            {
                var filter = new Windows.Web.Http.Filters.HttpBaseProtocolFilter();
                filter.ServerCredential = new Windows.Security.Credentials.PasswordCredential("BSE_Win10(1)", "mahonidatastream", "Maho1019");
                var client = new Windows.Web.Http.HttpClient(filter);
                string urlPath = "https://...m/user/auth";
                var values = new List<KeyValuePair<string, string>>
                {
                    new KeyValuePair<string, string>("email", emailBox.Text),
                    new KeyValuePair<string, string>("password",passwordBox.Password)
                };
                var response = await client.PostAsync(new Uri(urlPath), new Windows.Web.Http.HttpFormUrlEncodedContent(values));
                response.EnsureSuccessStatusCode();

                if (!response.IsSuccessStatusCode)
                {
                    //RequestException();
                    loadingLogin.IsActive = false;
                }

                string jsonText = await response.Content.ReadAsStringAsync();

                JsonObject jsonObject = JsonObject.Parse(jsonText);
                bool error = jsonObject["error"].GetBoolean();
                //string message = jsonObject["message"].GetString();
                if (error == false)
                {
                    LoginDialog.IsOpen = false;
                    FailedMessage.Visibility = Visibility.Collapsed;
                    ((App)(App.Current)).UserName = emailBox.Text;
                    loadingLogin.IsActive = false;
                }
                else
                {
                    FailedMessage.Visibility = Visibility.Visible;
                    FailedMessage.Text = "Email atau password tidak sesuai/belum terdaftar";
                    loadingLogin.IsActive = false;
                }

            }
            catch (HttpRequestException ex)
            {
                //ConnectionException();
                loadingLogin.IsActive = false;
            }
        }

  private void store_Tapped(object sender, TappedRoutedEventArgs e)
  {
      if (((App)(App.Current)).UserName == "Sign in to your account")
      {
          LoginDialog.IsOpen = true;
          loginDetail.Visibility = Visibility.Collapsed;
          loginEnter.Visibility = Visibility.Visible;
          emailBox.Text = "";
          passwordBox.Password = "";
          isstoreTapped = true;
          iskoleksiTapped = false;
      }
      else
      {
          this.Frame.Navigate(typeof(Store));
      }
  }

  private void koleksi_Tapped(object sender, TappedRoutedEventArgs e)
  {
      if (((App)(App.Current)).UserName == "Sign in to your account")
      {
          LoginDialog.IsOpen = true;
          loginDetail.Visibility = Visibility.Collapsed;
          loginEnter.Visibility = Visibility.Visible;
          emailBox.Text = "";
          passwordBox.Password = "";
          iskoleksiTapped = true;
          isstoreTapped = false;
      }
      else
      {
          this.Frame.Navigate(typeof(koleksibuku.KolesiPage));
      }
  }

**********更新********* 我的真实代码使用变量，建议的解决方案不起作用。见下文

 p = as.POSIXct("2016-12-15 20:11:29 PST")
 p

***这也是骗局工作

     p = as.POSIXct("2016-12-15 20:11:29 PST")
          out = as.POSIXct(p, tz="GMT")
          out
          attr(out,"tzone") <- "America/New_York"
          out

>           out
[1] "2016-12-15 20:11:29 PST"
>           attr(out,"tzone") <- "America/New_York"
>           out
[1] "2016-12-15 23:11:29 EST"  ### this is incorrect

Answer 1

我可以在那里找到你的大部分路，但R认为你对时差有误：

> p = as.POSIXct("2016-12-15 20:11:29 PST", usetz=TRUE, tz="GMT")
>  p
[1] "2016-12-15 20:11:29 GMT"
> (format(p, tz="America/New_York") )
[1] "2016-12-15 15:11:29"

对编辑的回应。我没有看到问题。 R中时间的数字表示总是GMT。您可以使用参数输入来删除错误的tz，但是format或strftime的输出只需要为不同的时区指定参数。（使用变量应该没有效果。）

 p = "2016-12-15 20:11:29 PST"
 pp = as.POSIXct(p, usetz=TRUE, tz="GMT")
 pp
[1] "2016-12-15 20:11:29 GMT"

Answer 2

您的问题是您的p默认位于您的系统时区：

p = as.POSIXct("2016-12-15 20:11:29 PST")
p
# I'm in Australian Eastern Standard Time, AEST
#[1] "2016-12-15 20:11:29 AEST"
as.numeric(p)
#[1] 1481796689

将此本地日期时间转换为UTC，通过格式化并将时区重置为GMT来更改基础数据（除非您已经在GMT中，否则它当然不会做任何事情）：

p2 <- as.POSIXct(format(p),tz="UTC")
p2
#[1] "2016-12-15 20:11:29 UTC"
as.numeric(p2)
#[1] 1481832689
p2 - p
#Time difference of 10 hours
# ...which is the difference between AEST and GMT

然后你可以调整时区属性，这只会改变日期/时间对象的显示。它不会影响基础数字数据：

attr(p2,"tzone") <- "America/New_York"
p2
#[1] "2016-12-15 15:11:29 EST"

as.numeric(p2)
#[1] 1481832689

转换不正确的时区

2 个答案: