Z*field Entries keep missing frequently in a STD SAP Table

[ricky_shaw]

Hi,
I am having some Z*fields like ZDATE1 & ZDATE2 type DATUM in a STD table ETTA.
I update the fields with some entries & saving and they keep disappearing frequently after few days.
So i have to use SE16N in debug mode to enter those 1000 entries again & again to those Z*DATE fields.
Can any one tell me why those values keep disappearing after few days?

[FabioPagoti]

Most likely there is a program (standard or custom) using a MODIFY in this table by using a structure which has your custom fields empty. I recommend doing a where used list on the table or use code scanner to search for such kind of statement.