Newbie here. I'm working on a report about San Antonio medical volunteers activated during Hurricane Harvey. To provide context I put together a timeline of events (in Excel) that happened over the one month period when the volunteers were active, including the date when Harvey hit the Texas coast, when the first San Antonio shelter opened, the day with the most number of volunteers, etc. I've looked at this discussion of timelines: Timeline graph but can't figure out how the first graph was created. Steps were skipped or assumptions were made. I'd like my timeline to look something like the one pictured (staggered above and below the axis). I don't want to use Gantt charts. I'm using Tableau desktop 2018. Can this even be done in Tableau?