A quick example on what $GPZDA messages are. Keep in mind that the sentence Identifier can also be displayed as $GNZDA. The message is the same but some GNSS receivers use this format.
Date & Time
UTC, day, month, year, and local time zone.
hhmmss.ss = UTC
xx = Day, 01 to 31
xx = Month, 01 to 12
xxxx = Year
xx = Local zone description, 00 to +/- 13 hours
xx = Local zone minutes description (same sign as hours)