Provider availability should be flexible

When a provider set his availability by default it set as 9am to 5pm.
I want to set multiple provider having there availability multiple times for particular day.

Example :
Provider A set his availability morning 09 am to 11 am.
Provider B set his availability morning 12 pm to 02 pm.
Provider C set his availability morning 03 pm to 04 pm.
Provider D set his availability morning 05 pm to 07 pm.

But when am setting availability for provider it getting set 9am to 5 pm. When I have changed setting from Administration -> global -> Calendar Calendar Starting Hour : 9am Calendar Ending Hour: 5pm then the calendar show that much time as selected in Calendar Ending Hour drop down list.

Can you please help me to sort out this issue. Am new in openemr.

Thanks
SK.