How to change the table value in run time based on some condition of the field?

Hi Team,

My requirement is user searches the value in service order search the result should be displayed in Result of service order.This is the field based on calculating System date - posting date.Example if we create service order on yesterday ,and posted date is today so that time The field value should be 1.if we check same order in next after 1 day the value should be 2.So that value should be changed as per calculating date and posting date.

So this field value doesn't save on data base.suppose if the value is stored in data base,if we see the field value on after two days it cant change,why because data base value should not change. so this functionality is not working here.

So How to achieve this,major part is user wants to search this field value on Between 1 - 20 like that so the value search should work perfectly.is there any Badi or tell me the steps how to do it?

Ageing = system-date - posting date

This value is stored in z table,same value we are displayed in service order search and result.

Thanks for advance.

Thanks&regards

Kalpana