### Summary <!-- Summarize the bug encountered concisely. --> When viewing burndown and burnup charts for Iteration Cadences, there is a bug that shows the trend line going backwards in time. ### Steps to reproduce - From Groups, go to Issues >> Iterations >> select an individual iteration - Look at burndown or burnup chart filtered by issues or issue weight ### What is the current *bug* behavior? - Burnup and burndown chart trend lines go backwards in time at the end of the trend line ### What is the expected *correct* behavior? - A burnup or burndown chart's trend line should not go backwards in time, only forwards ### Relevant logs and/or screenshots    ### Output of checks <!-- If you are reporting a bug on GitLab.com, uncomment below --> <!-- This bug happens on GitLab.com --> <!-- /label ~"reproduced on GitLab.com" --> #### Results of GitLab environment info <!-- Input any relevant GitLab environment information if needed. --> <details> <summary>Expand for output related to GitLab environment info</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:env:info`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`) </pre> </details> #### Results of GitLab application Check <!-- Input any relevant GitLab application check information if needed. --> <details> <summary>Expand for output related to the GitLab application check</summary> <pre> (For installations with omnibus-gitlab package run and paste the output of: `sudo gitlab-rake gitlab:check SANITIZE=true`) (For installations from source run and paste the output of: `sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true`) (we will only investigate if the tests are passing) </pre> </details> ### Possible fixes <!-- If you can, link to the line of code that might be responsible for the problem. -->