If a security officer's guard card expires on July 31 of this year, can they work legally using this card on that day?

The correct response is that a security officer can legally work using their guard card on the exact day it expires, which in this case is July 31. Expiration dates signify the last day on which the guard card is considered valid. Thus, as long as the officer adheres to all other applicable laws and regulations, they can perform their duties without penalty up until the end of that day.

It's important to note that once the clock strikes midnight at the start of August 1, the card would no longer be valid, and the officer would require either a renewed card or a valid temporary permit to continue working lawfully. This understanding is critical for security professionals to ensure they remain compliant with state regulations surrounding their licensing.