Inspection Interval Change

in My industry, we have inspection interval period as 180 days but now it is changed to 365 days. Even though the inspection interval changed from 180 days to 365 days, the material is going for recurring inspection in 180 days if the material have stock already before it changed to 365 days

material : XX

initial inspection interval :180

stock : 4 kg

after inspection interval change (to 365 days) also the material is going for recurring inspection in 180 days but in actual in will be inspected for 365 days but not 180 days.