与Google Apps脚本中的formatDate进行日期比较仅落后一天

Question

编写一个Google Apps脚本，通过Google Tasks API（作为高级服务）查看任务，并检查其截止日期以查看它们是否已过期。如果是，则应将它们移至当天。

已完成项目

我使用此代码创建此项目以保持Google Tasks的最新状态：

Keep Google Tasks Updated

问题

将当前日期与任务到期日期进行比较时，任务到期日始终落后一天。

研究

调查结果我发现它可能与夏令时有关，只需一小时就可能意味着两天内的差异。我发现this question有类似问题，他们的解决方案是使用Session.getScriptTimeZone()正确设置时区。

然而，即使我使用Session.getScriptTimeZone()设置时区，它仍然会将任务的截止日期推迟一天。

守则

function checkOverdue(t) {
  var today = Utilities.formatDate(new Date(), "EST", "MM/dd/yyyy");
  //var today = new Date();
  var tasks = t;
  if (tasks.items) {
    for (var i = 0; i < tasks.items.length; i++) {
      var task = tasks.items[i];
      if (task.due) {
        var taskDue = Utilities.formatDate(new Date(task.due), "EST", "MM/dd/yyyy");
        Logger.log('"%s", Comparing "%s" to "%s"',
                 task.title, taskDue, today);
        if (taskDue.valueOf() < today.valueOf()) {
          Logger.log('Task with title "%s" is past due', task.title);
        }
      }
    }
  } else {
    Logger.log('No tasks found.');
  }
}

日志

[18-04-10 13:12:33:927 EDT] "Create Bio presentation", Comparing "04/09/2018" to "04/10/2018"
[18-04-10 13:12:33:928 EDT] Task with title "Create Bio presentation" is past due
[18-04-10 13:12:33:929 EDT] "Bio Presentation", Comparing "04/10/2018" to "04/10/2018"
[18-04-10 13:12:33:930 EDT] "Matrix HW", Comparing "04/09/2018" to "04/10/2018"
[18-04-10 13:12:33:930 EDT] Task with title "Matrix HW" is past due

=== [更新] ===

我注意到如果我记录原始task.due，它似乎有正确的日期。所以关于格式化的一些事情是改变日期。

新代码

function checkOverdue(t) {
  var today = Utilities.formatDate(new Date(), "EST", "MM/dd/yyyy");
  //var today = new Date();
  var tasks = t;
  if (tasks.items) {
    for (var i = 0; i < tasks.items.length; i++) {
      var task = tasks.items[i];
      if (task.due) {
        var taskDue = Utilities.formatDate(new Date(task.due), "EST", "MM/dd/yyyy");
        Logger.log('"%s", Comparing TaskDue: "%s" to today: "%s", task.due "%s"', task.title, taskDue, today, task.due);
        if (taskDue.valueOf() < today.valueOf()) {
          Logger.log('Task with title "%s" is past due', task.title);
        }
      }
    }
  } else {
    Logger.log('No tasks found.');
  }
}

新日志

[18-04-10 14:15:17:628 EDT] "Create Bio presentation", Comparing TaskDue: "04/09/2018" to today: "04/10/2018", task.due "2018-04-10T00:00:00.000Z"
[18-04-10 14:15:17:629 EDT] Task with title "Create Bio presentation" is past due
[18-04-10 14:15:17:630 EDT] "Bio Presentation", Comparing TaskDue: "04/10/2018" to today: "04/10/2018", task.due "2018-04-11T00:00:00.000Z"
[18-04-10 14:15:17:631 EDT] "Matrix HW", Comparing TaskDue: "04/09/2018" to today: "04/10/2018", task.due "2018-04-10T00:00:00.000Z"
[18-04-10 14:15:17:631 EDT] Task with title "Matrix HW" is past due

=== [更新2] ===

将formatDate中的"EST"更改为Session.getScriptTimeZone()

删除.valueOf()进行比较。

仍然导致同样的问题

新代码

function checkOverdue(t) {
  var today = Utilities.formatDate(new Date(), Session.getScriptTimeZone(), "MM/dd/yyyy");
  //var today = new Date();
  var tasks = t;
  if (tasks.items) {
    for (var i = 0; i < tasks.items.length; i++) {
      var task = tasks.items[i];
      if (task.due) {
        var taskDue = Utilities.formatDate(new Date(task.due), Session.getScriptTimeZone(), "MM/dd/yyyy");
        Logger.log('"%s", Comparing TaskDue: "%s" to today: "%s", task.due "%s"', task.title, taskDue, today, task.due);
        if (taskDue < today) {
          Logger.log('Task with title "%s" is past due', task.title);
        }
      }
    }
  } else {
    Logger.log('No tasks found.');
  }
}

新日志

[18-04-10 15:21:01:988 EDT] "Create Bio presentation", Comparing TaskDue: "04/09/2018" to today: "04/10/2018", task.due "2018-04-10T00:00:00.000Z"
[18-04-10 15:21:01:988 EDT] Task with title "Create Bio presentation" is past due
[18-04-10 15:21:01:990 EDT] "Bio Presentation", Comparing TaskDue: "04/10/2018" to today: "04/10/2018", task.due "2018-04-11T00:00:00.000Z"
[18-04-10 15:21:01:991 EDT] "Matrix HW", Comparing TaskDue: "04/09/2018" to today: "04/10/2018", task.due "2018-04-10T00:00:00.000Z"
[18-04-10 15:21:01:991 EDT] Task with title "Matrix HW" is past due

Answer 1

根据Google Tasks API文档，task#due property是RFC 3339日期时间值，例如"2018-04-11T0:45:26.000Z"。 从这个字符串中，你可以原生地构造一个Javascript Date，即

var taskDueDate = new Date(task.due);

请注意，这相当于调用Date.parse()，因此可能是您的日期比较失败的原因，因为Google Apps脚本是Javascript 1.6（即不是ES5 +）。一个可能更好的方法是使用自定义解析器，因为您知道从task.due获得的严格特定格式。一个这样的解析器在this answer中有详细说明。

如@Serge所述，您应该使用原生Date个对象执行此比较，而不是Strings：

function isOverdue(task) {
  if(!task.due)
    return false;

  var now = new Date();
  var endOfToday = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), now.getUTCDate() + 1)); // Also known as start of tomorrow ;)
  var taskDueDate = myFunctionToConvertRFC3339StringToJSDate(task.due);
  return taskDueDate < endOfToday;
}

Answer 2

对于info，这是我用来转换RFC339时间对象的小代码。 我发现阅读和理解更容易。

function parseDate_RFC3339(string) {
  var refStr = new Date().toString();
  Logger.log('refStr = '+refStr);
  var tzOffset = Number(refStr.substr(refStr.indexOf('GMT')+4,2));
  Logger.log('TZ offset = '+tzOffset);
  var parts = string.split('T');
  parts[0] = parts[0].replace(/-/g, '/');
  var t = parts[1].split(':');
  return new Date(new Date(parts[0]).setHours(+t[0]+tzOffset,+t[1],0));
}