It is important to note that Sqwincher is a food product and not a medicinal product, therefore it falls under Food Standards Australia & New Zealand and BRC GLOBAL STANDARDS for FOOD SAFETY.
Most foods have a best-before date (BBD). You can still eat foods for a while after the best-before date as they should be safe but they may have lost some quality. Foods that have a best-before date can legally be sold after that date provided the food is fit for human consumption*.
*(Source: https://www.foodstandards.gov.au/consumer/labelling/dates/pages/default.aspx)