Single or multi series, they look like stacked bars (and they may have gaps), but they may repeat the same colors in the same timeline. Hard to repro with other types of charts (like Gantt).

References:
https://forum.highcharts.com/highcharts-usage/bar-chart-with-repeating-colors-t39445/
https://www.interworks.com/blog/ccapitula/2014/12/18/tableau-essentials-chart-types-gantt-chart
https://docs.inductiveautomation.com/display/DOC/Status+Chart
https://stackoverflow.com/questions/23223059/wpf-toolkit-stacked100barseries-chart
https://stackoverflow.com/questions/22191515/how-do-i-create-a-timeline-chart-in-excel
https://github.com/jiahuang/d3-timeline