To know when a gift card was used, print the sales report for that client.
First, click on File, Inventory and make sure the inventory item for GCPMT is attached to the correct category of GIFTCARDS.
Next, click on Reports, Revenue, Sales report.
Choose Detailed and Select One customer. Search for and select the right customer.
The beginning date should be the first date the card is used.
The report will list a section called Gift Card with the payments applied.