Paul --
Adding an "e" to preface a Duration value, such as 3 edays or 8 ehours,
means the time value is elapsed using a 24-hour calendar that ignores all
nonworking time. If you have a task that starts on Friday and has a
Duration of 3 days, the software schedules the task work for Friday, skips
Saturday and Sunday because they are nonworking time, and continues the task
work Monday and Tuesday of the following week. If you set the Duration of
the same task to 3 edays, the software schedules the task for Friday,
Saturday, and Sunday.
The "ehrs" designation means that you are measuring Duration in hours rather
than days, and also means that the Duration value ignores all nonworking
time. Now, my question for you is why this task is using "ehrs" for the
Duration.

Hope this helps.