missing calculation work day for html

[dev xmesoft com]

Hello developers,

I found problem in html output.
i.e.
Set to start time 10:00 to 13:00 and 14:00 to 17:00 (6 hour of day)
Insert a task need in gantt WBS and set to 4 days work.
After that extend output with html
check work day is 3 days  instead of 4 days.

Sample is attached.

Thanks,