Arrival Time is taken by default as 00.00.00 in VA02 when enter new item

Hi Experts,

When I entered new item in VA02, arrival time(vbep-ezeit) is by default 00.00.00 coming.

But How can I see where these value is assigning as zero.

and also please explain me how the GI Time, Loading Time and MATL LODGING TIME are assigning the valus.

regards,

Ramki