Must Finish On constraint is violated

[arcady-zherdev]

Steps to reproduce:

1. open advanced demo
2. choose "Business" as the project calendar in the toolbar
3. change "Install Apache" task duration to "1 day"
4. clear the task constraint type and date
5. set the task constraint to "Must finish on"
6. change the constraint date to "Jan 16, 2025"

Result: the task end date is "Jan 16, 2025 17:00"

bryntum.query('gantt').tasks[2].endDate

[maartenraes]

Original query from client

When a project has a calendar which defines the working hours, we see an issue with scheduling of task with must finish on constraint.
Changing constraintDate of the task results in it getting scheduled exactly 1 day early. Ideally what we understand from must finish on , is that the endDate would include working hours of the constraintDate . If I would only change the constraintType to must finish on , then the constraintDate is correct. But if I manually update the constraintDate, the endDate is exactly one day off. I have attached a video for better understanding.
I think whats happening is, manually changing constraintDate is setting time to be 00:00 hours , hence causing an issue while scheduling.

Gantt config

import {TaskModel} from "@bryntum/gantt-thin";

class MyTaskModel extends TaskModel {
    static get fields() {
        return [
            {name: 'importantDate', type: 'date'}
        ]
    }
}

const ganttProps = {
    // columns    : [{ type : 'name', field : 'name', width : 250 }],

    tooltip : "My cool Bryntum Gantt component",
    viewPreset : 'hourAndDay',
    barMargin  : 10,
    columns : [
        { type : 'wbs', hidden : true },
        { type : 'name', width : 250, showWbs : true },
        { type : 'startdate' },
        { type : 'enddate' },
        { type : 'duration' },
        { type : 'constrainttype' },
        { type : 'constraintdate' },
    ],
    filterFeature : true,
    project : {
        taskModelClass : MyTaskModel,
        transport : {
            load : {
                url : 'data/data.json',
            }
        },
        autoLoad           : true,
        // Automatically introduces a `startnoearlier` constraint for tasks that (a) have no predecessors, (b) do not use
        // constraints and (c) aren't `manuallyScheduled`
        autoSetConstraints : true
        ,
        timeRangeStore:true,
        stm : {
            autoRecord : true
        },
    },


};

export { ganttProps };

Data.json

{
  "success" : true,

  "project" : {
    "calendar"     : 777,
    "startDate"    : "2019-01-14",
    "endDate"    : "2019-01-18",
    "hoursPerDay"  : 8,
    "daysPerWeek"  : 5,
    "daysPerMonth" : 20
  },

  "calendars": {
    "rows": [
      {
        "id": 777,
        "name": "business",
        "intervals": [
          {
            "id"                 : 123,
            "recurrentStartDate" : "every weekday at 00:00",
            "recurrentEndDate"   : "every weekday at 13:00",
            "isWorking"          : false
          },
          {
            "id"                 : 456,
            "recurrentStartDate" : "every weekday at 21:00",
            "recurrentEndDate"   : "every weekday at 00:00",
            "isWorking"          : false
          }
        ]
      }
    ]
  },

  "tasks" : {
    "rows" : [
      {
        "id"          : 1000,
        "name"        : "task 1",
        "percentDone" : 50,
        "startDate"   : "2019-01-14T13:00:00",
        "endDate"   : "2019-01-14T21:00:00"
      }
    ]
  }
}

[ghulamghousdev]

Another report here: https://forum.bryntum.com/viewtopic.php?p=161411#p161411
Same reproduction steps as shown in the ticket description: https://codepen.io/udALMG/pen/XJrPyWN

[arcady-zherdev]

A related ticket for UI part is #10660