If you ever change the company schedule, it will also lead to the voicemail schedule needing to be changed.
To change the timings, click on one of your timings, a new screen pops up:-
To make changes, click a timer and click MODIFY.
This allows you to change the audio file, select the desired days and set the name of the time schedule.
If you need to add another time schedule, click ADD and input all of the details mentioned above.