See explanation below.
Explanation
You need to create a working time template and a working time calendar.
Create the template:
* Click Organization administration > Common > Calendars > Working time templates. Click New to create a new line.
* On the Overview tab, in the Working time template field, enter an alphanumeric identifier of up to 10 characters.
* In the Name field, enter a descriptive name for the template.
* Select the tab that corresponds to the day of the week that you want to define working hours for, and click Add to create a new line.
* In the From field, enter the starting time for the day or the period (09:00).
* In the To field, enter the ending time for the day or the period (17:00)
* Repeat steps 4 through 6 for each day of the week ensuring that Saturday and Sunday are marked as closed then save the template.
Create the calendar:
* Click Organization administration > Common > Calendars > Calendars.
* On the toolbar, click New to create a new line.
* In the Calendar field, enter a unique identifier of up to ten characters.
* In the Name field, enter Work Week.
* Click Working times, and then click Compose working times to create or update working times for the calendar.
* In the Calendar field, select the name of the calendar (Work Week) to compose working times for.
* In the From date field, enter the first date to compose working times for. By default, the field contains the current date.
* In the To date field, enter the last date to compose working times for. By default, the field contains a date that is one year from the current date.
* In the Working time template field, select the template you created.
* Click OK.
Reference:
https://docs.microsoft.com/en-us/dynamicsax-2012/appuser-itpro/create-working-time-templates
https://docs.microsoft.com/en-us/dynamicsax-2012/appuser-itpro/create-working-time-calendars