# How query over ignition historian for Gantt chart dataset

**URL:** <https://forum.inductiveautomation.com/t/how-query-over-ignition-historian-for-gantt-chart-dataset/44806>\
**Category:** Ignition\
**Created:** [March 23, 2021, 6:10pm UTC](https://forum.inductiveautomation.com/t/how-query-over-ignition-historian-for-gantt-chart-dataset/44806 "2021-03-23T18:10:23Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![nader.chinichian](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/nader.chinichian/32/9261_2.png) [@nader.chinichian](https://forum.inductiveautomation.com/u/nader.chinichian)\
**Post date:** [March 23, 2021, 6:10pm UTC](https://forum.inductiveautomation.com/t/how-query-over-ignition-historian-for-gantt-chart-dataset/44806/1 "2021-03-23T18:10:23Z")

</div>

Hi,  
I have some boolean tags that represent stations connection status (true = link ok, false=offline)  
I want to show them on a Gantt chart. The problem is I don’t know to query, so dataset is acceptable for Gnatt chart:

```auto
[{ station: 'A', 'fromDate': '2018-01-01 12:00', 'endDate': '2018-01-01 15:00'}, { station: 'A', 'fromDate': '2018-01-01 17:00', 'endDate': '2018-01-01 17:30'},
 { station: 'A', 'fromDate': '2018-01-02 17:00', 'endDate': '2018-01-02 17:30'}
]

```

the fromDate to endDate represents when the tag value is True.