This is where you have to dig a little deeper. Your receiver outputs the date in the NMEA messages, but the satellite doesn't actually transmit year/month/day.

This is where you have to dig a little deeper. Your receiver outputs the date in the NMEA messages, but the satellite doesn't actually transmit year/month/day. The satellite transmits the week number and the number of seconds that have passed since the start of the week. In your case, the receiver could potentially output incorrect dates in the NMEA output when the week number wraps around.