Burndown chart not following timesheet submissions

When I go to generate a burndown report for a project, it seems to be tracking workload at the time entries are made, instead of following dates that real work has been entered via the timesheet. For example, if on Thursday I enter timesheets for Monday - Wednesday, the burndown chart will show the same amount of work left M-W and then a sharp drop for Thursday.

Can this be toggled to respect the timesheet entries? I don't always have time at the end of a workday to input work for my team, but would like a realistic burndown chart based on when tasks are actually completed.

In our specific use case it is not feasible for team members to enter in their own times. This is a manufacturing setting where most do not have anything above basic computer skills, and we have multiple contracts that their resource pool is assigned to. They would be potentially choosing between over 300 different activities to enter their times.

Are the left work changes tracked using the host time or client-side time? In other words, if I change my computer's date to match when the work was actually done, will Left Work be updated using the "fake" time, or using the server-side time?