Changed
Investigate Work Time module.
Try building a time tracker using Flag and ECA.
Tried using datetime range for start/end time, but unable to create with only start value due to this issue:
View on Drupal.org #2794481Allow end date to be optional Status: Needs work
Smart date end date is also required: View on GitLab #3489072End time is Required Status: Active
Workaround by setting end date to start time on initial creation.
Working ECA:
