An opening instruction can be shorter than the printed unopened shelf life. Marking when a pack was opened helps you apply both limits correctly.
What the observation tells you
The printed date assumes its stated storage conditions. Opening changes those conditions for many products, so a long remaining date does not cancel an instruction to use promptly after opening. Transferring food into another container can hide that instruction altogether.
A useful next step
Keep the original storage information or copy the essential details onto the new container. Follow whichever applicable deadline comes first and maintain suitable refrigeration. A fresh-looking appearance cannot extend a safety-based use-by limit.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.