PlantUML also has gantt chart (https://plantuml.com/gantt-diagram ) support. unfortunately does not scale below days. There is a chronology diagram(https://plantuml.com/chronology-diagram) available but not linked from the main documentation or documented very much at all. Though it looks like the correct diagram in plantuml for the data in OP is a timing diagram (https://plantuml.com/timing-diagram)