If the code is 1, a positive leap second will be added at the end of the month. This means that the last minute of the month will contain 61 seconds instead of 60. If the code is 2, a second will be deleted on the last day of the month. Leap seconds occur at a rate of about one per year. They are used to correct for irregularity in the earth's rotation.
H is a health digit that indicates the health of the server.
This state should change to fully healthy within 10 minutes. The advance is currently set to 50.0 milliseconds. This simple protocol returns a 32-bit unformatted binary number that represents the time in UTC seconds since January 1, 1900. The 32-bit binary format can represent times over a span of about 136 years with a resolution of 1 second. There is no provision for increasing the resolution or increasing the range of years.