An example of the ZDA message string is:
|0||Message ID $GPZDA|
|2||Day, ranging between 01 and 31|
|3||Month, ranging between 01 and 12|
|5||Local time zone offset from GMT, ranging from 00 through ±13 hours|
|6||Local time zone offset from GMT, ranging from 00 through 59 minutes|
|7||The checksum data, always begins with *|
Fields 5 and 6 together yield the total offset. For example, if field 5 is -5 and field 6 is +15, local time is 5 hours and 15 minutes earlier than GMT.