Wasindikaji na expire date za bidhaa zao

Naomba kujua ivi hawa wajasiriamali wa majumbani, mfano wauza ubuyu, mikate, keki,mafuta ya alizeti, Asali etc wanajuaje kuhusu zile expire date wanazochapisha?

Ivi rate of decay calculation huwa wanazijua kweli?

Je hizo expire date zina ukweli gani?

Doing by gesture