In order to log time, a Task must first be available to the User that wishes to log their time.
This can be done by assigning the Task to a Team that the User is a part of.
Hint: Managers can log time for anyone even if they aren't assigned to that Task
When a Task is assigned, all members of that Team will receive a notification allowing them to quickly access that Task.
Once they have worked on that Task they will be able to log their time here:
This allows you to track multiple time entries from multiple people on multiple dates.
Extra Information: You need at least two users to create a team
To watch a brief tutorial no how to assign multiple people to a Task, watch this video.