That mocked data vis looks great! I think you should be able to create the visualization reasonably easily using a Line graph:
- Create a new Line visualization using the index that contains the data
- Use a Date Histogram as your x-axis aggregation with the timestamp as your field. You should be able to leave the minimum interval as auto (or change it later for more/less granularity).
- Use a count as your y-axis Metric
- Using the global filter option right at the top of the page, below the search bar, add a filter with Field = active and the value as true.
The visualization will give you a count of the number of 'active' items for each date because we're plotting all the items and then filtering out those that are closed.
If you want to plot the sum of items over time that are active, I recommend using TSVB with a filter ratio of the number of active items that are true divided by all the items we have by that date. You might need to create some additional fields to plot those values though (using a sum aggregation in a pipeline for the total doc count you have per date). There's a Discuss post that covered something similar here.
I hope that gives you what you're looking for.