How can i change time period like gantt chat in DHX scheduler?

How Can I change time period design and like start date and time and next field is duration so and time calculate by start DateTime and duration of events ??
I am stuck in this problem. Please help me.
@Polina @Siarhei @Aliaksandr

Hi @Rijwan_Mohammed

Yes, if you use Gantt chart, the end_date mandatory property can be replaced with duration as it described here.

As for the Scheduler - there are 3 mandatory properties: start_date, end_date, text and, unfortunately, end_date can’t be replaced with duration.