How query over ignition historian for Gantt chart dataset

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:

[{ 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.