Date Formats

When the Grid displays values, you need to ensure that the dates are rendered properly and saved in the database in the expected format.

Scenarios

The most common scenarios which cover the rendering of dates by the Grid are:

1. Showing the dates depending on the client timezone
2. Using UTC on both client and server
3. Allowing the user to customize the timezone

Showing Dates Depending on the Client Timezone

This scenario represents the default behavior of the Grid. The date objects are created on the client immediately after they are received from the server. Based on the current time, the default JavaScript date object automatically adds the time offset. This approach was chosen as default behavior because the date objects demonstrate the same default behavior and most users expect to see the date in its current timezone.

The following example demonstrates how to create different time with an offset depending on the current timezone.

  <p></p>
  <div id="grid"></div>
    <script>
      var newDate = new Date("2020-01-01T18:45");
      $('p').html(newDate);     
      $('#grid').kendoGrid({
        dataSource:{
          data:[{date: new Date("2020-01-01T18:45")}]
        }
      })
    </script>

Using UTC on Both Client and Server

The application of this scenario intends to display the date in a UTC timezone regardless of the user timezone. For a complete implementation of this behavior, refer to the article on setting the UTC timezone on both client and server.

Allowing the User to Customize the Timezone

The following example demonstrates how to allow the user to manually select the desired timezone.

    <div id="example">
      <p>Please choose a timezone: </p>
      <input id="timeZone" style="width: 100%;" />
      <hr />
      <div id="grid"></div>
      <script>

        currentoffsetMiliseconds = (new Date()).getTimezoneOffset() * 60000;
        offsetMiliseconds = 0;

        // Modify the current offset if the server is not in UTC
        // currentoffsetMiliseconds = ((new Date()).getTimezoneOffset() - 120) * 60000;

        $(document).ready(function() {

          var data = [
            { text: "GMT+1", value: "1" },
            { text: "GMT+2", value: "2" },
            { text: "GMT-1", value: "-1" },
            { text: "GMT-2", value: "-2" },
            { text: "GMT", value: "0" }
          ];

          $("#timeZone").kendoDropDownList({
            dataTextField: "text",
            dataValueField: "value",
            dataSource: data,
            index: 0,
            change:onChange
          });
          var dataSource = new kendo.data.DataSource({
            requestEnd:onRequestEnd,
            batch: true,
            transport: {
              read: {
                url: "https://demos.telerik.com/kendo-ui/service/tasks",
                dataType: "jsonp"
              },
              update: {
                url: "https://demos.telerik.com/kendo-ui/service/tasks/update",
                dataType: "jsonp"
              },
              create: {
                url: "https://demos.telerik.com/kendo-ui/service/tasks/create",
                dataType: "jsonp"
              },
              destroy: {
                url: "https://demos.telerik.com/kendo-ui/service/tasks/destroy",
                dataType: "jsonp"
              },
              parameterMap: function(options, operation) {

                var tizeZoneValue = $("#timeZone").data('kendoDropDownList').value();
                offsetMiliseconds = (3600000 * tizeZoneValue);

                // Remove the current timezone offset and add the offset choosen by the user in the DropDownList
                if ((operation == "update" || operation == "create") && options.models){
                  for(let i = 0; i < options.models.length; i++)
                  {
                    var startDate = new Date(options.models[i].Start);
                    startDate = new Date(startDate.getTime() - (currentoffsetMiliseconds + offsetMiliseconds));
                    options.models[i].Start = startDate;
                  }
                }
                if (operation !== "read" && options.models) {
                  return {models: kendo.stringify(options.models)};
                }
              }
            },
            schema: {
              model: {
                id: "taskId",
                fields: {
                  taskId: { from: "TaskID", type: "number" },
                  title: { from: "Title", defaultValue: "No title", validation: { required: true } },
                  start: { type: "date", from: "Start" },
                  end: { type: "date", from: "End" },
                  startTimezone: { from: "StartTimezone" },
                  endTimezone: { from: "EndTimezone" },
                  description: { from: "Description" },
                  recurrenceId: { from: "RecurrenceID" },
                  recurrenceRule: { from: "RecurrenceRule" },
                  recurrenceException: { from: "RecurrenceException" },
                  ownerId: { from: "OwnerID", defaultValue: 1 },
                  isAllDay: { type: "boolean", from: "IsAllDay" }
                }
              }
            }
          });

          $("#grid").kendoGrid({
            dataSource: dataSource,
            height: 430,
            toolbar: ["create", "save", "cancel"],
            editable:true,
            pageable: true,
            columns:[
              {field:"taskId", title: "Tast ID"},
              {field:"title", title: "Title"},
              {field:"start", title: "Start Date", format: "{0:MM/dd/yyyy h:mm tt}",editor: customDateTimePickerEditor},

            ]
          });
        });

        function onRequestEnd(e) {
          if (e.response && e.response.length) {
            var data = e.response;
            if (this.group().length && e.type == "read") {
              handleGroups(data);
            } else {              
              loopRecords(data);
            }
          }
        }

        function onChange(e){
          $("#grid").data('kendoGrid').dataSource.read()
        }

        function handleGroups(groups) {
          for (var i = 0; i < groups.length; i++) {
            var gr = groups[i];
            offsetDateFields(gr);
            if (gr.HasSubgroups) {
              handleGroups(gr.Items)
            } else {
              loopRecords(gr.Items);
            }
          }
        }
        function loopRecords(records) {
          for (var i = 0; i < records.length; i++) {
            var record = records[i];
            offsetDateFields(record);
          }
        }

        function offsetDateFields(obj) {
          var tizeZoneValue = $("#timeZone").data('kendoDropDownList').value();
          for (var name in obj) {
            var prop = obj[name];
            // The following replace method is needed because the dates are received from the server in the following format "/Date(1500469281437)/"
            if (typeof (prop) === "string" && prop.indexOf("/Date(") == 0) {
              obj[name] = prop.replace(/\d+/, function (n) {     

                // Calculate the offset based on the user selection in the DropDownList
                offsetMiliseconds = (3600000 * tizeZoneValue);

                // Remove the current timezone offset and add the offset choose by the user in the DropDownList
                return parseInt(n) + offsetMiliseconds + currentoffsetMiliseconds;
              });
            }
          }
        }

        function customDateTimePickerEditor(container, options) {
          $('<input required name="' + options.field + '"/>')
            .appendTo(container)
            .kendoDateTimePicker({});
        }
      </script>
    </div>