There is no universal storage period for every mixed product. The water container label and the reconstituted medication label are separate sources of instructions.
Unopened container
Follow the manufacturer expiration date and labeled storage conditions. Do not use a container that is damaged, cloudy, discolored, or otherwise questionable.
After first puncture
CDC summarizes USP guidance that an opened multi-dose vial is generally dated and discarded within 28 days unless the manufacturer states another period. This general rule does not override a shorter product-specific limit.
After reconstitution
The stability and storage period of the mixed product can be much shorter and depends on the exact medication, diluent, concentration, container, temperature, light exposure, and validated labeling.